Merge pull request #67 from AmanTahiliani/phase-2

Phase 2 delivery — Replay & Storytelling, Driver & Rivalry Hub, Between-Races

.agents/skills/groom/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: groom
-description: Groom a box-box GitHub issue into a Ready spec via a seeded grill-me interrogation. Use when the user asks to groom an issue, for example "/groom <issue-number>" or "$groom <issue-number>" with optional "--lens architect". Single-issue path: asks targeted questions, writes a structured spec into the issue body, sets Effort/Priority, and leaves Stage at Research for approval.
+description: 'Groom a box-box GitHub issue into a Ready spec via a seeded grill-me interrogation. Use when the user asks to groom an issue, for example "/groom <issue-number>" or "$groom <issue-number>" with optional "--lens architect". Single-issue path: asks targeted questions, writes a structured spec into the issue body, sets Effort/Priority, and leaves Stage at Research for approval.'
 argument-hint: <issue-number> [--lens architect]
 ---
 

.agents/skills/implement/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: implement
-description: Dispatch a Ready box-box issue to a coding harness (claude/codex/opencode/pi/cursor) in an isolated git worktree, run the build gate, and open a PR. Use when supervising implementation via "/implement <issue-number> --harness <name> [--dry-run]" or from any harness terminal with .agents/bin/dev.
+description: 'Dispatch a Ready box-box issue to a coding harness (claude/codex/opencode/pi/cursor) in an isolated git worktree, run the build gate, and open a PR. Use when supervising implementation via "/implement <issue-number> --harness <name> [--dry-run]" or from any harness terminal with .agents/bin/dev.'
 argument-hint: <issue-number> --harness <claude|codex|opencode|pi|cursor> [--dry-run]
 ---
 

.agents/skills/lens-architect/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: lens-architect
-description: Grill/analyze a box-box issue or epic from a software-architecture perspective and post the findings as a comment. Use standalone as "/lens-architect <issue-number>" for an on-the-fly architecture review, or let /groom compose it via "--lens architect". Reads the base grill + architect persona and focuses on reuse, data flow, seams, testability, and risk.
+description: 'Grill/analyze a box-box issue or epic from a software-architecture perspective and post the findings as a comment. Use standalone as "/lens-architect <issue-number>" for an on-the-fly architecture review, or let /groom compose it via "--lens architect". Reads the base grill + architect persona and focuses on reuse, data flow, seams, testability, and risk.'
 argument-hint: <issue-number>
 ---
 

.agents/skills/review/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: review
-description: Locally review a box-box PR against its linked GitHub issue spec, run tests, capture visual screenshots when applicable, create a .review packet, and post a GitHub PR comment. Use when a ticket implementation is ready for independent local review before the human merge gate.
+description: 'Locally review a box-box PR against its linked GitHub issue spec, run tests, capture visual screenshots when applicable, create a .review packet, and post a GitHub PR comment. Use when a ticket implementation is ready for independent local review before the human merge gate.'
 argument-hint: <pr-number> [--harness <name>] [--publish-screenshots]
 ---
 

.agents/skills/write-spec/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: write-spec
-description: Render a groomed design into the box-box Ready-spec template and write it into a GitHub issue body, then set Effort and Priority. Called by /groom after a grill session, or run standalone as "/write-spec <issue-number>" to (re)write an issue's spec from agreed decisions. Does not change Stage.
+description: 'Render a groomed design into the box-box Ready-spec template and write it into a GitHub issue body, then set Effort and Priority. Called by /groom after a grill session, or run standalone as "/write-spec <issue-number>" to (re)write an issue''s spec from agreed decisions. Does not change Stage.'
 argument-hint: <issue-number>
 ---
 

frontend/src/api.ts

@@ -2,12 +2,16 @@ import type {
   ArticleContent,
   CarDataSample,
   ChampionshipHub,
+  DriverSummary,
+  EnrichedGrid,
+  EnrichedResult,
   LapsComparisonResponse,
   LiveStateResponse,
   LiveSessionMeta,
   Meeting,
   NewsItem,
   RaceHub,
+  ReplayFramesResponse,
   Session,
   TrackOutline,
   Weekend,
@@ -40,7 +44,11 @@ export async function fetchLocalMeetings(year: number): Promise<Meeting[]> {
 }
 
 export async function fetchSeasonMeetings(year: number): Promise<Meeting[]> {
-  const res = await fetch(`/api/v1/meetings?year=${year}&source=openf1`)
+  return fetchMeetings(year, 'openf1')
+}
+
+export async function fetchMeetings(year: number, source = 'auto'): Promise<Meeting[]> {
+  const res = await fetch(`/api/v1/meetings?year=${year}&source=${source}`)
   if (!res.ok) {
     throw new Error(`API ${res.status}: ${res.statusText}`)
   }
@@ -48,6 +56,47 @@ export async function fetchSeasonMeetings(year: number): Promise<Meeting[]> {
   return Array.isArray(meetings) ? meetings : []
 }
 
+export async function fetchResults(sessionKey: number, source = 'auto'): Promise<EnrichedResult[]> {
+  const res = await fetch(`/api/v1/results?session_key=${sessionKey}&source=${source}`)
+  if (!res.ok) {
+    throw new Error(`API ${res.status}: ${res.statusText}`)
+  }
+  const results = await res.json()
+  return Array.isArray(results) ? results : []
+}
+
+export async function fetchStartingGrid(sessionKey: number, source = 'auto'): Promise<EnrichedGrid[]> {
+  const res = await fetch(`/api/v1/grid?session_key=${sessionKey}&source=${source}`)
+  if (!res.ok) {
+    throw new Error(`API ${res.status}: ${res.statusText}`)
+  }
+  const grid = await res.json()
+  return Array.isArray(grid) ? grid : []
+}
+
+export async function fetchTrackOutline(circuitKey: number, year: number): Promise<TrackOutline | null> {
+  const res = await fetch(`/api/v1/track-outline?circuit_key=${circuitKey}&year=${year}`)
+  if (!res.ok) return null
+  const data = await res.json()
+  if (data?.error || !Array.isArray(data?.points) || data.points.length < 2) return null
+  return data as TrackOutline
+}
+
+export async function fetchReplayFrames(
+  sessionKey: number,
+  intervalMs = 5000,
+): Promise<ReplayFramesResponse> {
+  const params = new URLSearchParams({
+    session_key: String(sessionKey),
+    interval_ms: String(intervalMs),
+  })
+  const res = await fetch(`/api/v1/replay/frames?${params}`)
+  if (!res.ok) {
+    throw new Error(`API ${res.status}: ${res.statusText}`)
+  }
+  return res.json()
+}
+
 export async function fetchSessions(meetingKey: number, source = 'openf1'): Promise<Session[]> {
   const res = await fetch(`/api/v1/sessions?meeting_key=${meetingKey}&source=${source}`)
   if (!res.ok) {
@@ -76,6 +125,19 @@ export async function fetchChampionshipHub(year?: number): Promise<ChampionshipH
   return res.json()
 }
 
+export async function fetchDriverSummary(
+  driverNumber: number,
+  year?: number,
+): Promise<DriverSummary> {
+  const params = new URLSearchParams({ driver_number: String(driverNumber) })
+  if (year) params.set('year', String(year))
+  const res = await fetch(`/api/v1/driver/summary?${params.toString()}`)
+  if (!res.ok) {
+    throw new Error(`API ${res.status}: ${res.statusText}`)
+  }
+  return res.json()
+}
+
 export async function fetchLiveState(): Promise<LiveStateResponse> {
   const res = await fetch('/api/v1/live/state')
   if (!res.ok) {

frontend/src/components/ChapterStrip.tsx

@@ -0,0 +1,87 @@
+import type { Chapter } from '../types'
+import {
+  activeChapterIndex,
+  chapterKindLabel,
+  chapterLapRange,
+  chapterStartScrub,
+} from '../lib/chapters'
+import '../styles/chapters.css'
+
+interface Props {
+  chapters: Chapter[]
+  scrubTime: number | null
+  tMin: number
+  tRange: number
+  tourActive: boolean
+  tourChapterIndex: number | null
+  onChapterClick: (index: number, scrub: number) => void
+  onTourToggle: () => void
+}
+
+export function ChapterStrip({
+  chapters,
+  scrubTime,
+  tMin,
+  tRange,
+  tourActive,
+  tourChapterIndex,
+  onChapterClick,
+  onTourToggle,
+}: Props) {
+  if (chapters.length === 0) {
+    return (
+      <div className="chapter-strip" data-testid="chapter-strip">
+        <p className="chapter-strip-empty">No story chapters for this session.</p>
+      </div>
+    )
+  }
+
+  const activeIndex = activeChapterIndex(chapters, scrubTime, tMin, tRange)
+
+  return (
+    <div className="chapter-strip" data-testid="chapter-strip">
+      <div className="chapter-strip-header">
+        <span className="chapter-strip-title">Race chapters</span>
+        <div className="chapter-strip-actions">
+          <button
+            type="button"
+            className={`chapter-tour-btn ${tourActive ? 'active' : ''}`}
+            onClick={onTourToggle}
+            aria-pressed={tourActive}
+          >
+            {tourActive ? 'Exit 90s' : '90s tour'}
+          </button>
+        </div>
+      </div>
+      <div className="chapter-strip-scroll" role="list" aria-label="Race story chapters">
+        {chapters.map((chapter, index) => {
+          const scrub = chapterStartScrub(chapter, tMin, tRange) ?? index / Math.max(chapters.length - 1, 1)
+          const isActive = tourActive
+            ? tourChapterIndex === index
+            : activeIndex === index
+          const headline = chapter.headline || chapter.title
+
+          return (
+            <button
+              key={`${chapter.kind}-${chapter.start_lap}-${index}`}
+              type="button"
+              role="listitem"
+              className={`chapter-card ${isActive ? (tourActive ? 'tour-active' : 'active') : ''}`}
+              onClick={() => onChapterClick(index, scrub)}
+              aria-current={isActive ? 'true' : undefined}
+              data-testid={`chapter-card-${index}`}
+            >
+              <div className="chapter-card-top">
+                <span className={`chapter-kind chapter-kind--${chapter.kind}`}>
+                  {chapterKindLabel(chapter.kind)}
+                </span>
+                <span className="chapter-lap-range">{chapterLapRange(chapter)}</span>
+              </div>
+              <span className="chapter-headline">{headline}</span>
+            </button>
+          )
+        })}
+      </div>
+    </div>
+  )
+}

frontend/src/components/Nav.tsx

@@ -16,6 +16,9 @@ export function Nav() {
         <Link to="/race-hub" search={{}} activeProps={{ className: 'active' }}>
           Race Hub
         </Link>
+        <Link to="/preview" activeProps={{ className: 'active' }}>
+          Preview
+        </Link>
         <Link to="/championship" activeProps={{ className: 'active' }}>
           Championship
         </Link>

frontend/src/components/PaddockBriefing.tsx

@@ -1,7 +1,23 @@
+import { useMemo } from 'react'
 import { useQuery } from '@tanstack/react-query'
 import { Link } from '@tanstack/react-router'
-import { fetchNews } from '../api'
+import {
+  fetchChampionshipHub,
+  fetchNews,
+  fetchSeasonMeetings,
+  fetchSeasons,
+} from '../api'
+import {
+  activeDigestWindow,
+  gpWindows,
+  itemsForWindow,
+  sinceLastLabel,
+  tagColour,
+  tagItems,
+  topTags,
+} from '../lib/digest'
 import { timeAgo } from '../utils'
+import '../styles/digest.css'
 
 const SOURCE_DISPLAY: Record<string, string> = {
   'fia': 'FIA',
@@ -14,14 +30,53 @@ const SOURCE_DISPLAY: Record<string, string> = {
 }
 
 export function PaddockBriefing() {
+  const now = useMemo(() => new Date(), [])
+
   const { data: news, isLoading, isError } = useQuery({
     queryKey: ['news'],
     queryFn: () => fetchNews(100),
     staleTime: 60_000,
   })
 
+  const seasonsQuery = useQuery({
+    queryKey: ['seasons'],
+    queryFn: fetchSeasons,
+  })
+  const latestSeason = seasonsQuery.data?.[0] ?? null
+
+  const meetingsQuery = useQuery({
+    queryKey: ['season-meetings', latestSeason],
+    queryFn: () => fetchSeasonMeetings(latestSeason!),
+    enabled: latestSeason != null,
+  })
+
+  const hubQuery = useQuery({
+    queryKey: ['championship-hub', latestSeason],
+    queryFn: () => fetchChampionshipHub(latestSeason!),
+    enabled: latestSeason != null,
+  })
+
+  const meetings = meetingsQuery.data ?? []
+  const hub = hubQuery.data
+  const tagged = useMemo(
+    () => tagItems(news ?? [], hub?.drivers ?? [], hub?.teams ?? []),
+    [news, hub],
+  )
+
+  const windows = useMemo(() => gpWindows(meetings, now), [meetings, now])
+  const activeWindow = useMemo(
+    () => activeDigestWindow(windows, meetings, now),
+    [windows, meetings, now],
+  )
+  const sinceItems = useMemo(
+    () => itemsForWindow(tagged, activeWindow),
+    [tagged, activeWindow],
+  )
+  const sinceTags = useMemo(() => topTags(sinceItems, 4), [sinceItems])
+  const sinceLabel = sinceLastLabel(meetings, now)
+
   const unreadCount = news?.filter((i) => !i.read_at).length ?? 0
-  const preview = news?.slice(0, 5) ?? []
+  const preview = sinceItems.length > 0 ? sinceItems.slice(0, 5) : (tagged.slice(0, 5))
 
   return (
     <section className="cc-briefing" data-testid="paddock-briefing">
@@ -37,6 +92,27 @@ export function PaddockBriefing() {
         </Link>
       </div>
 
+      {meetings.length > 0 && (
+        <div className="cc-brief-digest-meta" data-testid="cc-brief-digest-meta">
+          <span>Since {sinceLabel}</span>
+          <span>·</span>
+          <span>{sinceItems.length} items</span>
+          {sinceTags.length > 0 && (
+            <div className="cc-brief-digest-tags">
+              {sinceTags.map((tag) => (
+                <span
+                  key={tag.key}
+                  className="cc-brief-tag"
+                  style={{ borderColor: tagColour(tag.colour) }}
+                >
+                  {tag.label}
+                </span>
+              ))}
+            </div>
+          )}
+        </div>
+      )}
+
       {isLoading && <div className="briefing-state loading-state">loading…</div>}
       {isError && <div className="briefing-state error-box">Failed to load briefing</div>}
 

frontend/src/components/RaceStoryCanvas.tsx

@@ -1,6 +1,13 @@
-import { useState, useMemo, useRef, useCallback } from 'react'
-import type { EnrichedResult, EnrichedGrid, PositionSample, Lap, Session } from '../types'
+import { useEffect, useMemo, useRef, useState } from 'react'
+import { useQuery } from '@tanstack/react-query'
+import type { Driver, EnrichedResult, EnrichedGrid, PositionSample, Lap, Meeting, Session, Chapter } from '../types'
+import { fetchReplayFrames, fetchTrackOutline } from '../api'
+import { ReplayTrackMap } from './ReplayTrackMap'
+import { ChapterStrip } from './ChapterStrip'
 import { gridDelta, gridDeltaClass, formatDuration, formatGap } from '../utils'
+import { chapterEndScrub, chapterStartScrub, chapterTourDurations } from '../lib/chapters'
+
+const CHAPTER_TOUR_MS = 90_000
 
 interface Props {
   data: {
@@ -12,28 +19,181 @@ interface Props {
     race_control?: any[]
     pit_stops?: any[]
     session?: Session
+    meeting?: Meeting
+    drivers?: Driver[]
+    chapters?: Chapter[]
   }
 }
 
 export function RaceStoryCanvas({ data }: Props) {
-  const { results, starting_grid: grid, positions, datasets, race_control = [], pit_stops = [], laps = [] } = data
+  const {
+    results,
+    starting_grid: grid,
+    positions,
+    datasets,
+    race_control = [],
+    pit_stops = [],
+    laps = [],
+    session,
+    meeting,
+    drivers = [],
+    chapters = [],
+  } = data
   const hasPositions = datasets['positions']?.status === 'available'
 
   const [scrubTime, setScrubTime] = useState<number | null>(null)
   const [hoverDriver, setHoverDriver] = useState<number | null>(null)
+  const [mapOpen, setMapOpen] = useState(false)
+  const [isPlaying, setIsPlaying] = useState(false)
+  const [playbackSpeed, setPlaybackSpeed] = useState(10)
+  const [chapterTourActive, setChapterTourActive] = useState(false)
+  const [tourChapterIndex, setTourChapterIndex] = useState<number | null>(null)
   const svgRef = useRef<SVGSVGElement>(null)
+  const tourRef = useRef({ chapterIndex: 0, startedAt: 0, durationMs: 0, startScrub: 0, endScrub: 0 })
 
   // Position Evolution Chart Logic
   const allTimes = useMemo(() => [...new Set(positions.map((p) => p.date))].sort(), [positions])
   const hasChartData = hasPositions && allTimes.length > 0
+  const chartTiming = useMemo(() => {
+    if (!hasChartData) return null
+    const tMin = new Date(allTimes[0]).getTime()
+    const tMax = new Date(allTimes[allTimes.length - 1]).getTime()
+    return { tMin, tMax, tRange: Math.max(tMax - tMin, 1) }
+  }, [allTimes, hasChartData])
+  const circuitKey = session?.circuit_key ?? meeting?.circuit_key ?? 0
+  const outlineYear = meeting?.year ?? (session?.date_start ? new Date(session.date_start).getFullYear() : 0)
+
+  const replayQuery = useQuery({
+    queryKey: ['replay-frames', session?.session_key, 5000],
+    queryFn: () => fetchReplayFrames(session!.session_key, 5000),
+    enabled: mapOpen && Boolean(session?.session_key),
+  })
+  const outlineQuery = useQuery({
+    queryKey: ['track-outline', circuitKey, outlineYear],
+    queryFn: () => fetchTrackOutline(circuitKey, outlineYear),
+    enabled: mapOpen && circuitKey > 0 && outlineYear > 0,
+  })
+
+  useEffect(() => {
+    if (!isPlaying || !chartTiming) return
+
+    let frame = 0
+    let last = performance.now()
+    const tick = (now: number) => {
+      const delta = now - last
+      last = now
+      setScrubTime((current) => {
+        const next = Math.min(1, (current ?? 0) + (delta * playbackSpeed) / chartTiming.tRange)
+        if (next >= 1) {
+          setIsPlaying(false)
+        }
+        return next
+      })
+      frame = requestAnimationFrame(tick)
+    }
+
+    frame = requestAnimationFrame(tick)
+    return () => cancelAnimationFrame(frame)
+  }, [chartTiming, isPlaying, playbackSpeed])
+
+  const stopChapterTour = () => {
+    setChapterTourActive(false)
+    setTourChapterIndex(null)
+  }
+
+  const jumpToChapter = (index: number, scrub: number) => {
+    setIsPlaying(false)
+    stopChapterTour()
+    setScrubTime(scrub)
+  }
+
+  const toggleChapterTour = () => {
+    if (chapterTourActive) {
+      stopChapterTour()
+      return
+    }
+    if (!chartTiming || chapters.length === 0) return
+    setIsPlaying(false)
+    setChapterTourActive(true)
+    setTourChapterIndex(0)
+    const startScrub = chapterStartScrub(chapters[0], chartTiming.tMin, chartTiming.tRange) ?? 0
+    setScrubTime(startScrub)
+    const durations = chapterTourDurations(chapters, CHAPTER_TOUR_MS)
+    tourRef.current = {
+      chapterIndex: 0,
+      startedAt: performance.now(),
+      durationMs: durations[0] ?? CHAPTER_TOUR_MS / chapters.length,
+      startScrub,
+      endScrub: chapterEndScrub(chapters[0], chartTiming.tMin, chartTiming.tRange) ?? startScrub,
+    }
+  }
+
+  useEffect(() => {
+    if (!chapterTourActive || !chartTiming || chapters.length === 0) return
+
+    let frame = 0
+    const tick = (now: number) => {
+      const state = tourRef.current
+      const elapsed = now - state.startedAt
+      const progress = Math.min(1, elapsed / Math.max(state.durationMs, 1))
+      const scrub = state.startScrub + (state.endScrub - state.startScrub) * progress
+      setScrubTime(scrub)
+      setTourChapterIndex(state.chapterIndex)
+
+      if (progress >= 1) {
+        const nextIndex = state.chapterIndex + 1
+        if (nextIndex >= chapters.length) {
+          stopChapterTour()
+          return
+        }
+        const durations = chapterTourDurations(chapters, CHAPTER_TOUR_MS)
+        const startScrub = chapterStartScrub(chapters[nextIndex], chartTiming.tMin, chartTiming.tRange) ?? 0
+        const endScrub = chapterEndScrub(chapters[nextIndex], chartTiming.tMin, chartTiming.tRange) ?? startScrub
+        tourRef.current = {
+          chapterIndex: nextIndex,
+          startedAt: now,
+          durationMs: durations[nextIndex] ?? CHAPTER_TOUR_MS / chapters.length,
+          startScrub,
+          endScrub,
+        }
+      }
+      frame = requestAnimationFrame(tick)
+    }
+
+    frame = requestAnimationFrame(tick)
+    return () => cancelAnimationFrame(frame)
+  }, [chapterTourActive, chartTiming, chapters])
+
+  useEffect(() => {
+    if (!chapterTourActive) return
+    const onKeyDown = (event: KeyboardEvent) => {
+      if (event.key === 'Escape') {
+        stopChapterTour()
+      }
+    }
+    window.addEventListener('keydown', onKeyDown)
+    return () => window.removeEventListener('keydown', onKeyDown)
+  }, [chapterTourActive])
+
+  const replayTMs = useMemo(() => {
+    const replay = replayQuery.data
+    const frames = replay?.frames ?? []
+    if (frames.length === 0) return 0
+    const lastFrameT = frames[frames.length - 1].t
+    const progress = scrubTime ?? 0
+    if (!chartTiming || !replay?.start_time) {
+      return Math.max(0, Math.min(lastFrameT, Math.round(progress * lastFrameT)))
+    }
+    const replayStart = new Date(replay.start_time).getTime()
+    const chartTime = chartTiming.tMin + progress * chartTiming.tRange
+    return Math.max(0, Math.min(lastFrameT, Math.round(chartTime - replayStart)))
+  }, [chartTiming, replayQuery.data, scrubTime])
 
   let chartContent = null
   let displayResults = results
 
-  if (hasChartData) {
-    const tMin = new Date(allTimes[0]).getTime()
-    const tMax = new Date(allTimes[allTimes.length - 1]).getTime()
-    const tRange = Math.max(tMax - tMin, 1)
+  if (hasChartData && chartTiming) {
+    const { tMin, tRange } = chartTiming
 
     const byDriver = new Map<number, Array<{ t: number; pos: number }>>()
     for (const p of positions) {
@@ -137,6 +297,8 @@ export function RaceStoryCanvas({ data }: Props) {
     }
 
     const handlePointerMove = (e: React.PointerEvent<SVGRectElement>) => {
+      setIsPlaying(false)
+      stopChapterTour()
       if (!svgRef.current) return
       const rect = svgRef.current.getBoundingClientRect()
       const x = e.clientX - rect.left
@@ -288,24 +450,91 @@ export function RaceStoryCanvas({ data }: Props) {
             height={plotH}
             fill="transparent"
             onPointerMove={handlePointerMove}
-            onPointerLeave={() => setScrubTime(null)}
+            onPointerLeave={() => {
+              if (!isPlaying) setScrubTime(null)
+            }}
             style={{ cursor: 'crosshair', touchAction: 'none' }}
           />
         </svg>
+        <div className="rs-replay-tools" aria-label="Race replay controls">
+          <button
+            type="button"
+            className={`rs-tool-btn ${isPlaying ? 'active' : ''}`}
+            onClick={() => {
+              setScrubTime((current) => current ?? 0)
+              stopChapterTour()
+              setIsPlaying((current) => !current)
+            }}
+          >
+            {isPlaying ? 'Pause' : 'Play'}
+          </button>
+          <div className="rs-speed-group" aria-label="Playback speed">
+            {[1, 10, 30].map((speed) => (
+              <button
+                key={speed}
+                type="button"
+                className={`rs-speed-btn ${playbackSpeed === speed ? 'active' : ''}`}
+                onClick={() => setPlaybackSpeed(speed)}
+              >
+                {speed}x
+              </button>
+            ))}
+          </div>
+          <button
+            type="button"
+            className={`rs-tool-btn ${mapOpen ? 'active' : ''}`}
+            onClick={() => setMapOpen((current) => !current)}
+          >
+            Map
+          </button>
+        </div>
       </div>
     )
   }
 
   return (
     <div className="race-story-canvas">
-      {hasChartData ? (
-        chartContent
-      ) : (
-        <div className="analysis-notice">
-          <strong>Lap-by-lap positions not available.</strong> This session does not
-          have ingested position samples in <code>/api/v1/race-hub</code>.
-        </div>
+      {hasChartData && chartTiming && chapters.length > 0 && (
+        <ChapterStrip
+          chapters={chapters}
+          scrubTime={scrubTime}
+          tMin={chartTiming.tMin}
+          tRange={chartTiming.tRange}
+          tourActive={chapterTourActive}
+          tourChapterIndex={tourChapterIndex}
+          onChapterClick={jumpToChapter}
+          onTourToggle={toggleChapterTour}
+        />
       )}
+      <div className="rs-replay-shell">
+        <div className="rs-replay-main">
+          {hasChartData ? (
+            chartContent
+          ) : (
+            <div className="analysis-notice">
+              <strong>Lap-by-lap positions not available.</strong> This session does not
+              have ingested position samples in <code>/api/v1/race-hub</code>.
+            </div>
+          )}
+        </div>
+        {mapOpen && (
+          <div className="rs-replay-map-slot">
+            {circuitKey > 0 && outlineYear > 0 ? (
+              <ReplayTrackMap
+                outline={outlineQuery.data}
+                replay={replayQuery.data}
+                tMs={replayTMs}
+                drivers={drivers}
+                results={results}
+                loading={outlineQuery.isLoading || replayQuery.isLoading}
+                error={outlineQuery.isError || replayQuery.isError}
+              />
+            ) : (
+              <div className="rs-replay-map-placeholder">track identity unavailable for replay map</div>
+            )}
+          </div>
+        )}
+      </div>
 
       {displayResults.length > 0 && (
         <div className="rs-field-list">

frontend/src/components/ReplayTrackMap.tsx

@@ -0,0 +1,133 @@
+import { useMemo, useState } from 'react'
+import type { Driver, EnrichedResult, ReplayFramesResponse, TrackOutline } from '../types'
+import { buildOutlinePath } from '../lib/trackmap'
+import { interpolateReplayCars, replayCarToSvg } from '../lib/replay'
+import '../styles/replay-map.css'
+
+interface Props {
+  outline?: TrackOutline | null
+  replay?: ReplayFramesResponse | null
+  tMs: number
+  drivers: Driver[]
+  results: EnrichedResult[]
+  loading?: boolean
+  error?: boolean
+}
+
+export function ReplayTrackMap({
+  outline,
+  replay,
+  tMs,
+  drivers,
+  results,
+  loading = false,
+  error = false,
+}: Props) {
+  const [pinned, setPinned] = useState<string | null>(null)
+  const outlinePath = useMemo(() => buildOutlinePath(outline?.points ?? []), [outline])
+  const driverInfo = useMemo(() => {
+    const info = new Map<string, { label: string; color: string }>()
+    for (const driver of drivers) {
+      info.set(String(driver.driver_number), {
+        label: driver.name_acronym || String(driver.driver_number),
+        color: normalizeColor(driver.team_colour),
+      })
+    }
+    for (const result of results) {
+      const key = String(result.driver_number)
+      if (!info.has(key)) {
+        info.set(key, {
+          label: result.name_acronym || key,
+          color: normalizeColor(result.team_colour),
+        })
+      }
+    }
+    return info
+  }, [drivers, results])
+
+  const cars = useMemo(() => {
+    if (!outline?.bounds || !replay?.frames?.length) return []
+    const positions = interpolateReplayCars(replay.frames, tMs)
+    return Object.entries(positions)
+      .map(([number, car]) => ({
+        number,
+        svg: replayCarToSvg(car, outline.bounds),
+        info: driverInfo.get(number),
+      }))
+      .sort((a, b) => Number(a.number) - Number(b.number))
+  }, [driverInfo, outline?.bounds, replay?.frames, tMs])
+
+  if (loading) {
+    return (
+      <section className="replay-map-panel" data-testid="replay-track-map">
+        <div className="replay-map-empty">loading replay GPS...</div>
+      </section>
+    )
+  }
+
+  if (error) {
+    return (
+      <section className="replay-map-panel" data-testid="replay-track-map">
+        <div className="replay-map-empty">replay GPS unavailable for this session</div>
+      </section>
+    )
+  }
+
+  if (!outline || !outlinePath) {
+    return (
+      <section className="replay-map-panel" data-testid="replay-track-map">
+        <div className="replay-map-empty">track outline unavailable for this session</div>
+      </section>
+    )
+  }
+
+  if (!replay?.frames?.length || cars.length === 0) {
+    return (
+      <section className="replay-map-panel" data-testid="replay-track-map">
+        <div className="replay-map-empty">historical GPS unavailable for this session</div>
+      </section>
+    )
+  }
+
+  return (
+    <section className="replay-map-panel" data-testid="replay-track-map">
+      <div className="replay-map-stage">
+        <svg className="replay-map-svg" viewBox="0 0 100 100" role="img" aria-label="Replay track map">
+          <path className="replay-map-outline-shadow" d={outlinePath} />
+          <path className="replay-map-outline" d={outlinePath} />
+          {cars.map((car) => {
+            const label = car.info?.label ?? car.number
+            const selected = pinned === car.number
+            return (
+              <g
+                key={car.number}
+                role="button"
+                tabIndex={0}
+                aria-label={`${label} replay position`}
+                className={`replay-car ${selected ? 'replay-car-pinned' : ''}`}
+                transform={`translate(${car.svg.x.toFixed(2)} ${car.svg.y.toFixed(2)})`}
+                onClick={() => setPinned(selected ? null : car.number)}
+                onKeyDown={(event) => {
+                  if (event.key === 'Enter' || event.key === ' ') {
+                    event.preventDefault()
+                    setPinned(selected ? null : car.number)
+                  }
+                }}
+              >
+                <title>{label}</title>
+                <circle r="2.7" fill={car.info?.color ?? '#777777'} />
+                <text y="0.85">{label}</text>
+              </g>
+            )
+          })}
+        </svg>
+      </div>
+    </section>
+  )
+}
+
+function normalizeColor(color: string | undefined): string {
+  const raw = color?.trim()
+  if (!raw) return '#777777'
+  return raw.startsWith('#') ? raw : `#${raw}`
+}

frontend/src/components/RivalryCompare.tsx

@@ -0,0 +1,271 @@
+import { useMemo, useState } from 'react'
+import type { ChampHubDriver, ChampionshipHub } from '../types'
+import { teamColor } from '../utils'
+import { gapSeries, h2hTally, lastRounds } from '../lib/rivalry'
+import '../styles/rivalry.css'
+
+const PAD_L = 48
+const PAD_T = 16
+const PLOT_W = 882
+const PLOT_H = 316
+const GAP_PLOT_H = 200
+
+function fmtPts(n: number): string {
+  return Number.isInteger(n) ? String(n) : n.toFixed(1)
+}
+
+/** Up to ~7 evenly spaced round labels, always including the last round. */
+function xTicks(n: number, labels: string[], x: (i: number) => number): { x: number; label: string }[] {
+  const step = Math.max(1, Math.ceil(n / 7))
+  const ticks: { x: number; label: string }[] = []
+  for (let i = 0; i < n; i += step) {
+    ticks.push({ x: x(i), label: labels[i] ?? `R${i + 1}` })
+  }
+  const last = labels[n - 1] ?? `R${n}`
+  if (ticks[ticks.length - 1]?.label !== last) {
+    ticks.push({ x: x(n - 1), label: last })
+  }
+  return ticks
+}
+
+function polyline(values: number[], x: (i: number) => number, y: (v: number) => number): string {
+  return values.map((v, i) => `${x(i).toFixed(1)},${y(v).toFixed(1)}`).join(' ')
+}
+
+interface PickerProps {
+  id: 'a' | 'b'
+  label: string
+  drivers: ChampHubDriver[]
+  value: number
+  color: string
+  onChange: (driverNumber: number) => void
+}
+
+function DriverPicker({ id, label, drivers, value, color, onChange }: PickerProps) {
+  return (
+    <label className="rivalry-picker">
+      <span className="rivalry-picker-label">{label}</span>
+      <select
+        className="rivalry-picker-select"
+        style={{ borderLeft: `3px solid ${color}` }}
+        value={value}
+        data-testid={`rivalry-pick-${id}`}
+        onChange={(e) => onChange(Number(e.target.value))}
+      >
+        {drivers.map((d) => (
+          <option key={d.driver_number} value={d.driver_number}>
+            {d.name_acronym} · {d.full_name}
+          </option>
+        ))}
+      </select>
+    </label>
+  )
+}
+
+export function RivalryCompare({ hub }: { hub: ChampionshipHub }) {
+  const { drivers } = hub
+  const [pickA, setPickA] = useState<number | null>(null)
+  const [pickB, setPickB] = useState<number | null>(null)
+
+  // Default to the top two in the standings; fall back there if a picked
+  // driver disappears (e.g. season switch re-fetches the hub).
+  const a = drivers.find((d) => d.driver_number === pickA) ?? drivers[0]
+  const b = drivers.find((d) => d.driver_number === pickB) ?? drivers[1]
+
+  const tally = useMemo(
+    () => (a && b ? h2hTally(a.round_positions ?? [], b.round_positions ?? [], hub.round_labels) : null),
+    [a, b, hub.round_labels],
+  )
+
+  if (drivers.length < 2) {
+    return (
+      <div className="champ-chart-empty" data-testid="champ-view-rivalry">
+        Need at least two drivers in the standings to compare a rivalry.
+      </div>
+    )
+  }
+
+  const colorA = teamColor(a.team_colour)
+  const colorB = teamColor(b.team_colour)
+  const sameTeam = a.team_name === b.team_name
+
+  const cumA = a.cumulative ?? []
+  const cumB = b.cumulative ?? []
+  const rounds = Math.min(cumA.length, cumB.length)
+  const gaps = gapSeries(cumA, cumB)
+  const lastGap = gaps[gaps.length - 1] ?? 0
+  const strip = tally ? lastRounds(tally, 5) : []
+
+  const pickers = (
+    <div className="rivalry-pickers">
+      <DriverPicker id="a" label="Driver A" drivers={drivers} value={a.driver_number} color={colorA} onChange={setPickA} />
+      <span className="rivalry-vs mono">vs</span>
+      <DriverPicker id="b" label="Driver B" drivers={drivers} value={b.driver_number} color={colorB} onChange={setPickB} />
+    </div>
+  )
+
+  if (rounds === 0) {
+    return (
+      <div className="rivalry" data-testid="champ-view-rivalry">
+        {pickers}
+        <div className="champ-chart-empty">
+          No completed rounds yet — the rivalry will appear after the first race.
+        </div>
+      </div>
+    )
+  }
+
+  // Points race scales.
+  const peak = Math.max(...cumA.slice(0, rounds), ...cumB.slice(0, rounds), 1)
+  const maxY = Math.max(50, Math.ceil(peak / 50) * 50)
+  const px = (i: number) => (rounds <= 1 ? PAD_L : PAD_L + (i * PLOT_W) / (rounds - 1))
+  const py = (v: number) => PAD_T + PLOT_H - (v / maxY) * PLOT_H
+  const pyGrid = [0, 0.25, 0.5, 0.75, 1].map((f) => ({ y: py(maxY * f), label: Math.round(maxY * f) }))
+  const pxGrid = xTicks(rounds, hub.round_labels, px)
+
+  // Gap scales: symmetric around zero.
+  const maxAbs = Math.max(10, Math.ceil(Math.max(...gaps.map(Math.abs), 1) / 10) * 10)
+  const gy = (v: number) => PAD_T + GAP_PLOT_H / 2 - (v / maxAbs) * (GAP_PLOT_H / 2)
+  const gyGrid = [maxAbs, 0, -maxAbs].map((v) => ({ y: gy(v), label: v > 0 ? `+${v}` : String(v) }))
+  const gxGrid = xTicks(rounds, hub.round_labels, px)
+
+  const gapLeader = lastGap === 0 ? null : lastGap > 0 ? a : b
+  const gapCaption = gapLeader
+    ? `${gapLeader.name_acronym} leads by ${fmtPts(Math.abs(lastGap))} pts after ${hub.round_labels[rounds - 1] ?? `R${rounds}`}.`
+    : 'Dead level on points.'
+
+  return (
+    <div className="rivalry" data-testid="champ-view-rivalry">
+      {pickers}
+
+      <div className="rivalry-h2h" data-testid="rivalry-h2h">
+        <div className="rivalry-h2h-score">
+          <span className="rivalry-h2h-code mono" style={{ color: colorA }}>
+            {a.name_acronym}
+          </span>
+          <span className="rivalry-h2h-num mono" data-testid="rivalry-h2h-num">
+            {tally ? `${tally.a}–${tally.b}` : '—'}
+          </span>
+          <span className="rivalry-h2h-code mono" style={{ color: colorB }}>
+            {b.name_acronym}
+          </span>
+        </div>
+        <span className="rivalry-h2h-meta">
+          Race head-to-head · {tally?.rounds.length ?? 0} round{(tally?.rounds.length ?? 0) === 1 ? '' : 's'} counted
+          {tally && tally.skipped > 0 ? ` · ${tally.skipped} skipped` : ''}
+        </span>
+        {strip.length > 0 && (
+          <div className="rivalry-strip" data-testid="rivalry-strip">
+            <span className="rivalry-strip-label">Last {strip.length}</span>
+            {strip.map((r) => (
+              <span className="rivalry-chip" key={r.round} title={`${r.label}: ${a.name_acronym} P${r.posA} · ${b.name_acronym} P${r.posB}`}>
+                <span className="rivalry-chip-round mono">{r.label}</span>
+                <span className="rivalry-chip-winner mono" style={{ color: r.winner === 'a' ? colorA : colorB }}>
+                  {r.winner === 'a' ? a.name_acronym : b.name_acronym}
+                </span>
+              </span>
+            ))}
+          </div>
+        )}
+      </div>
+
+      <section className="rivalry-section" data-testid="rivalry-points-race">
+        <div className="champ-chart-head">
+          <span className="champ-chart-title mono">
+            Points race — {a.name_acronym} vs {b.name_acronym}
+          </span>
+          <span className="champ-chart-meta">
+            Rounds 1–{rounds} · {hub.season}
+          </span>
+        </div>
+        <div className="champ-chart">
+          <svg viewBox="0 0 1000 380" className="champ-chart-svg" preserveAspectRatio="none">
+            {pyGrid.map((g) => (
+              <g key={g.label}>
+                <line x1={PAD_L} y1={g.y} x2={930} y2={g.y} stroke="var(--border)" strokeWidth="1" />
+                <text x={40} y={g.y + 4} textAnchor="end" className="champ-chart-axis">
+                  {g.label}
+                </text>
+              </g>
+            ))}
+            {pxGrid.map((g, i) => (
+              <text key={i} x={g.x} y={372} textAnchor="middle" className="champ-chart-axis">
+                {g.label}
+              </text>
+            ))}
+            {[
+              { slot: 'a', d: a, color: colorA, dash: '0', values: cumA.slice(0, rounds) },
+              { slot: 'b', d: b, color: colorB, dash: sameTeam ? '5 4' : '0', values: cumB.slice(0, rounds) },
+            ].map((s) => (
+              <g key={s.slot}>
+                <polyline
+                  points={polyline(s.values, px, py)}
+                  fill="none"
+                  stroke={s.color}
+                  strokeWidth="2.4"
+                  strokeDasharray={s.dash}
+                  strokeLinejoin="round"
+                  strokeLinecap="round"
+                />
+                <circle cx={px(s.values.length - 1)} cy={py(s.values[s.values.length - 1])} r="3" fill={s.color} />
+                <text
+                  x={px(s.values.length - 1) + 8}
+                  y={py(s.values[s.values.length - 1]) + 4}
+                  fill={s.color}
+                  className="champ-chart-label"
+                >
+                  {s.d.name_acronym}
+                </text>
+              </g>
+            ))}
+          </svg>
+        </div>
+      </section>
+
+      <section className="rivalry-section" data-testid="rivalry-gap">
+        <div className="champ-chart-head">
+          <span className="champ-chart-title mono">
+            Gap over season — {a.name_acronym} − {b.name_acronym}
+          </span>
+          <span className="champ-chart-meta">{gapCaption}</span>
+        </div>
+        <div className="champ-chart">
+          <svg viewBox="0 0 1000 250" className="champ-chart-svg" preserveAspectRatio="none">
+            {gyGrid.map((g) => (
+              <g key={g.label}>
+                <line
+                  x1={PAD_L}
+                  y1={g.y}
+                  x2={930}
+                  y2={g.y}
+                  stroke={g.label === '0' ? 'var(--border-2)' : 'var(--border)'}
+                  strokeWidth={g.label === '0' ? 1.5 : 1}
+                />
+                <text x={40} y={g.y + 4} textAnchor="end" className="champ-chart-axis">
+                  {g.label}
+                </text>
+              </g>
+            ))}
+            {gxGrid.map((g, i) => (
+              <text key={i} x={g.x} y={242} textAnchor="middle" className="champ-chart-axis">
+                {g.label}
+              </text>
+            ))}
+            <polyline
+              points={polyline(gaps, px, gy)}
+              fill="none"
+              stroke={colorA}
+              strokeWidth="2.4"
+              strokeLinejoin="round"
+              strokeLinecap="round"
+            />
+            <circle cx={px(gaps.length - 1)} cy={gy(lastGap)} r="3" fill={colorA} />
+          </svg>
+        </div>
+        <p className="rivalry-caption">
+          Above the zero line: {a.name_acronym} ahead. Below: {b.name_acronym} ahead.
+        </p>
+      </section>
+    </div>
+  )
+}

frontend/src/components/TeammateH2H.tsx

@@ -0,0 +1,55 @@
+import { teamColor } from '../utils'
+import '../styles/h2h.css'
+
+export interface TeammateH2HProps {
+  teamName: string
+  teamColour: string
+  driverATla: string
+  driverBTla: string
+  winsA: number
+  winsB: number
+  /** e.g. "+1" when more than two drivers share the team. */
+  extraNote?: string
+}
+
+export function TeammateH2H({
+  teamName,
+  teamColour,
+  driverATla,
+  driverBTla,
+  winsA,
+  winsB,
+  extraNote,
+}: TeammateH2HProps) {
+  const total = winsA + winsB || 1
+  const pctA = (winsA / total) * 100
+  const color = teamColor(teamColour)
+
+  return (
+    <div className="h2h-row" data-testid="teammate-h2h">
+      <div className="h2h-team">
+        <span className="h2h-team-name">{teamName}</span>
+        {extraNote ? <span className="h2h-extra mono">{extraNote}</span> : null}
+      </div>
+      <div className="h2h-bar-wrap">
+        <span className="h2h-tla h2h-tla--left mono">{driverATla}</span>
+        <div className="h2h-bar" data-testid="h2h-bar">
+          <span
+            className="h2h-bar-seg"
+            data-testid="h2h-bar-a"
+            style={{ width: `${pctA}%`, background: color }}
+          />
+          <span
+            className="h2h-bar-seg h2h-bar-seg--muted"
+            data-testid="h2h-bar-b"
+            style={{ width: `${100 - pctA}%`, background: color }}
+          />
+          <span className="h2h-score mono" data-testid="h2h-score">
+            {winsA}–{winsB}
+          </span>
+        </div>
+        <span className="h2h-tla h2h-tla--right mono">{driverBTla}</span>
+      </div>
+    </div>
+  )
+}

frontend/src/lib/chapters.ts

@@ -0,0 +1,82 @@
+import type { Chapter } from '../types'
+
+export function chapterKindLabel(kind: string): string {
+  switch (kind) {
+    case 'start':
+      return 'GO'
+    case 'safety_car':
+      return 'SC'
+    case 'virtual_safety_car':
+      return 'VSC'
+    case 'red_flag':
+      return 'RF'
+    case 'pit_phase':
+      return 'PIT'
+    case 'decisive_swing':
+      return '▲'
+    case 'finish':
+      return 'FIN'
+    default:
+      return kind.slice(0, 3).toUpperCase()
+  }
+}
+
+export function chapterLapRange(chapter: Chapter): string {
+  if (chapter.start_lap === chapter.end_lap) {
+    return `L${chapter.start_lap}`
+  }
+  return `L${chapter.start_lap}–L${chapter.end_lap}`
+}
+
+/** Normalized scrub position (0–1) for a chapter's start time on the chart axis. */
+export function chapterStartScrub(
+  chapter: Chapter,
+  tMin: number,
+  tRange: number,
+): number | null {
+  if (!chapter.start_time || tRange <= 0) return null
+  const ms = new Date(chapter.start_time).getTime()
+  if (Number.isNaN(ms)) return null
+  return Math.max(0, Math.min(1, (ms - tMin) / tRange))
+}
+
+/** Normalized scrub position (0–1) for a chapter's end time on the chart axis. */
+export function chapterEndScrub(
+  chapter: Chapter,
+  tMin: number,
+  tRange: number,
+): number | null {
+  const raw = chapter.end_time ?? chapter.start_time
+  if (!raw || tRange <= 0) return null
+  const ms = new Date(raw).getTime()
+  if (Number.isNaN(ms)) return null
+  return Math.max(0, Math.min(1, (ms - tMin) / tRange))
+}
+
+/** Index of the chapter containing the current scrub position, if any. */
+export function activeChapterIndex(
+  chapters: Chapter[],
+  scrubTime: number | null,
+  tMin: number,
+  tRange: number,
+): number | null {
+  if (scrubTime === null || chapters.length === 0 || tRange <= 0) return null
+  const chartMs = tMin + scrubTime * tRange
+  for (let i = 0; i < chapters.length; i++) {
+    const ch = chapters[i]
+    const startMs = ch.start_time ? new Date(ch.start_time).getTime() : NaN
+    const endRaw = ch.end_time ?? ch.start_time
+    const endMs = endRaw ? new Date(endRaw).getTime() : NaN
+    if (!Number.isNaN(startMs) && !Number.isNaN(endMs) && chartMs >= startMs && chartMs <= endMs) {
+      return i
+    }
+  }
+  return null
+}
+
+/** Duration in ms each chapter should play during a ~90s tour. */
+export function chapterTourDurations(chapters: Chapter[], totalMs = 90_000): number[] {
+  if (chapters.length === 0) return []
+  const perChapter = totalMs / chapters.length
+  return chapters.map(() => perChapter)
+}

frontend/src/lib/digest.ts

@@ -0,0 +1,293 @@
+import { meetingEndTime, meetingStartTime, mostRecentPastMeeting, nextUpcomingMeeting } from './schedule'
+import type { ChampHubDriver, ChampHubTeam, Meeting, NewsItem } from '../types'
+
+export interface GPWindow {
+  meeting_key: number
+  meeting_name: string
+  /** Inclusive lower bound: end of previous GP, or open for season opener. */
+  start: Date | null
+  /** Exclusive upper bound: start of next GP, or open after the final round. */
+  end: Date | null
+}
+
+export interface DigestTag {
+  kind: 'driver' | 'team'
+  key: string
+  label: string
+  colour: string
+}
+
+export type TaggedNewsItem = NewsItem & { tags: DigestTag[] }
+
+export const RECENT_BUCKET_KEY = '__recent__'
+
+interface MatchCandidate {
+  start: number
+  end: number
+  tag: DigestTag
+}
+
+interface TagPattern {
+  pattern: string
+  tag: DigestTag
+}
+
+function sortMeetings(meetings: Meeting[]): Meeting[] {
+  return [...meetings].sort((a, b) => {
+    const left = meetingStartTime(a)?.getTime() ?? 0
+    const right = meetingStartTime(b)?.getTime() ?? 0
+    if (left !== right) return left - right
+    return a.meeting_name.localeCompare(b.meeting_name)
+  })
+}
+
+/** Derive inter-race windows [prev GP end → next GP start] for each round. */
+export function gpWindows(meetings: Meeting[], _now: Date): GPWindow[] {
+  const sorted = sortMeetings(meetings)
+  return sorted.map((meeting, index) => ({
+    meeting_key: meeting.meeting_key,
+    meeting_name: meeting.meeting_name,
+    start: index > 0 ? meetingEndTime(sorted[index - 1]) : null,
+    end: index < sorted.length - 1 ? meetingStartTime(sorted[index + 1]) : null,
+  }))
+}
+
+function itemPublishedAt(item: NewsItem): Date | null {
+  if (!item.published_at) return null
+  const parsed = Date.parse(item.published_at)
+  return Number.isNaN(parsed) ? null : new Date(parsed)
+}
+
+function itemInWindow(published: Date, window: GPWindow): boolean {
+  if (window.start && published < window.start) return false
+  if (window.end && published >= window.end) return false
+  return true
+}
+
+export function windowForDate(windows: GPWindow[], published: Date): GPWindow | null {
+  const matches = windows.filter((window) => itemInWindow(published, window))
+  if (matches.length === 0) return null
+  return matches.reduce((best, window) => {
+    const bestStart = best.start?.getTime() ?? Number.NEGATIVE_INFINITY
+    const windowStart = window.start?.getTime() ?? Number.NEGATIVE_INFINITY
+    return windowStart >= bestStart ? window : best
+  })
+}
+
+export interface GroupedDigest {
+  windows: Array<{ window: GPWindow; items: NewsItem[] }>
+  recent: NewsItem[]
+}
+
+/** Bucket news items into GP windows; undated items land in `recent`. */
+export function groupByWindow(items: NewsItem[], windows: GPWindow[]): GroupedDigest {
+  const buckets = new Map<number, NewsItem[]>()
+  const recent: NewsItem[] = []
+
+  for (const item of items) {
+    const published = itemPublishedAt(item)
+    if (!published) {
+      recent.push(item)
+      continue
+    }
+    const match = windowForDate(windows, published)
+    if (!match) {
+      recent.push(item)
+      continue
+    }
+    const list = buckets.get(match.meeting_key) ?? []
+    list.push(item)
+    buckets.set(match.meeting_key, list)
+  }
+
+  const grouped = windows
+    .map((window) => ({
+      window,
+      items: buckets.get(window.meeting_key) ?? [],
+    }))
+    .filter((entry) => entry.items.length > 0)
+
+  return { windows: grouped, recent }
+}
+
+function driverLastName(fullName: string): string | null {
+  const parts = fullName.trim().split(/\s+/).filter(Boolean)
+  if (parts.length < 2) return null
+  return parts[parts.length - 1] ?? null
+}
+
+function buildTagPatterns(drivers: ChampHubDriver[], teams: ChampHubTeam[]): TagPattern[] {
+  const patterns: TagPattern[] = []
+
+  for (const team of teams) {
+    if (!team.team_name.trim()) continue
+    patterns.push({
+      pattern: team.team_name.toLowerCase(),
+      tag: {
+        kind: 'team',
+        key: `team:${team.team_name}`,
+        label: team.team_name,
+        colour: team.team_colour,
+      },
+    })
+  }
+
+  for (const driver of drivers) {
+    const colour = driver.team_colour
+    const base = {
+      kind: 'driver' as const,
+      colour,
+    }
+    if (driver.full_name.trim()) {
+      patterns.push({
+        pattern: driver.full_name.toLowerCase(),
+        tag: {
+          ...base,
+          key: `driver:${driver.name_acronym}`,
+          label: driver.name_acronym,
+        },
+      })
+      const lastName = driverLastName(driver.full_name)
+      if (lastName) {
+        patterns.push({
+          pattern: lastName.toLowerCase(),
+          tag: {
+            ...base,
+            key: `driver:${driver.name_acronym}`,
+            label: driver.name_acronym,
+          },
+        })
+      }
+    }
+    if (driver.name_acronym.trim()) {
+      patterns.push({
+        pattern: driver.name_acronym.toLowerCase(),
+        tag: {
+          ...base,
+          key: `driver:${driver.name_acronym}`,
+          label: driver.name_acronym,
+        },
+      })
+    }
+  }
+
+  patterns.sort((a, b) => b.pattern.length - a.pattern.length)
+  return patterns
+}
+
+function overlaps(a: MatchCandidate, b: MatchCandidate): boolean {
+  return a.start < b.end && b.start < a.end
+}
+
+/**
+ * Tag items via case-insensitive substring match on title + summary.
+ * Longest pattern wins on overlapping spans (v1 string match — no NLP).
+ *
+ * Known limitations: common-word last names, team names inside other words,
+ * and driver TLAs that appear in unrelated acronyms can false-positive.
+ */
+export function tagItems(
+  items: NewsItem[],
+  drivers: ChampHubDriver[],
+  teams: ChampHubTeam[],
+): TaggedNewsItem[] {
+  const patterns = buildTagPatterns(drivers, teams)
+
+  return items.map((item) => {
+    const haystack = `${item.title} ${item.summary ?? ''}`.toLowerCase()
+    const accepted: MatchCandidate[] = []
+
+    for (const { pattern, tag } of patterns) {
+      if (!pattern) continue
+      let from = 0
+      while (from <= haystack.length - pattern.length) {
+        const index = haystack.indexOf(pattern, from)
+        if (index === -1) break
+        const candidate: MatchCandidate = {
+          start: index,
+          end: index + pattern.length,
+          tag,
+        }
+        if (!accepted.some((match) => overlaps(match, candidate))) {
+          accepted.push(candidate)
+        }
+        from = index + 1
+      }
+    }
+
+    const tagsByKey = new Map<string, DigestTag>()
+    for (const match of accepted) {
+      tagsByKey.set(match.tag.key, match.tag)
+    }
+
+    return {
+      ...item,
+      tags: [...tagsByKey.values()].sort((a, b) => a.label.localeCompare(b.label)),
+    }
+  })
+}
+
+export function activeDigestWindow(
+  windows: GPWindow[],
+  meetings: Meeting[],
+  now: Date,
+): GPWindow | null {
+  const next = nextUpcomingMeeting(meetings, now)
+  if (next) {
+    return windows.find((window) => window.meeting_key === next.meeting_key) ?? null
+  }
+  const recent = mostRecentPastMeeting(meetings, now)
+  if (recent) {
+    return windows.find((window) => window.meeting_key === recent.meeting_key) ?? null
+  }
+  return windows[0] ?? null
+}
+
+export function sinceLastLabel(meetings: Meeting[], now: Date): string {
+  const last = mostRecentPastMeeting(meetings, now)
+  if (last) return last.meeting_name
+  const next = nextUpcomingMeeting(meetings, now)
+  if (next) return `Before ${next.meeting_name}`
+  return 'Pre-season'
+}
+
+export function itemsForWindow(items: TaggedNewsItem[], window: GPWindow | null): TaggedNewsItem[] {
+  if (!window) return []
+  return items.filter((item) => {
+    const published = itemPublishedAt(item)
+    return published != null && itemInWindow(published, window)
+  })
+}
+
+export function topTags(items: TaggedNewsItem[], limit = 5): DigestTag[] {
+  const counts = new Map<string, { tag: DigestTag; count: number }>()
+  for (const item of items) {
+    for (const tag of item.tags) {
+      const current = counts.get(tag.key)
+      if (current) current.count += 1
+      else counts.set(tag.key, { tag, count: 1 })
+    }
+  }
+  return [...counts.values()]
+    .sort((a, b) => b.count - a.count || a.tag.label.localeCompare(b.tag.label))
+    .slice(0, limit)
+    .map((entry) => entry.tag)
+}
+
+export function filterByTag(items: TaggedNewsItem[], tagKey: string | null): TaggedNewsItem[] {
+  if (!tagKey) return items
+  return items.filter((item) => item.tags.some((tag) => tag.key === tagKey))
+}
+
+export function tagColour(colour: string): string {
+  if (!colour) return 'var(--text-3)'
+  return colour.startsWith('#') ? colour : `#${colour}`
+}
+
+export function sortWindowBucketsNewestFirst<T extends { window: GPWindow }>(buckets: T[]): T[] {
+  return [...buckets].sort((a, b) => {
+    const left = a.window.start?.getTime() ?? 0
+    const right = b.window.start?.getTime() ?? 0
+    return right - left
+  })
+}

frontend/src/lib/driverProfile.ts

@@ -0,0 +1,69 @@
+import type { DriverSummaryRound } from '../types'
+
+/** One round mapped for the grid-vs-finish chart and results table. */
+export interface RoundDelta {
+  round: number // 1-based round index within the completed season
+  label: string // short GP label, e.g. "Bahrain"
+  grid: number | null
+  finish: number | null
+  /** grid − finish: positive = places gained on Sunday, null when unknowable. */
+  delta: number | null
+  points: number
+  status: 'classified' | 'dnf' | 'dns' | 'dsq' | 'absent'
+}
+
+/** Strip the "Grand Prix" boilerplate so round labels fit chart axes. */
+export function shortGpLabel(meetingName: string): string {
+  const short = meetingName
+    .replace(/\s*grand prix\s*/i, ' ')
+    .replace(/\s+gp\s*$/i, ' ')
+    .trim()
+  return short || meetingName
+}
+
+function roundStatus(r: DriverSummaryRound): RoundDelta['status'] {
+  if (r.dns) return 'dns'
+  if (r.dsq) return 'dsq'
+  if (r.dnf) return 'dnf'
+  if (r.race_position <= 0 && r.grid_position <= 0) return 'absent'
+  return 'classified'
+}
+
+/**
+ * Map summary rounds to grid-vs-finish deltas. Positions of 0 mean "no data"
+ * (driver absent, pit-lane start, …) and become null; a delta is only computed
+ * when both ends are known and the driver actually started the race.
+ */
+export function gridFinishDeltas(rounds: DriverSummaryRound[]): RoundDelta[] {
+  return rounds.map((r, i) => {
+    const status = roundStatus(r)
+    const grid = r.grid_position > 0 ? r.grid_position : null
+    const finish = r.race_position > 0 ? r.race_position : null
+    const delta =
+      grid != null && finish != null && status !== 'dns' && status !== 'absent'
+        ? grid - finish
+        : null
+    return {
+      round: i + 1,
+      label: shortGpLabel(r.meeting_name),
+      grid,
+      finish,
+      delta,
+      points: r.points,
+      status,
+    }
+  })
+}
+
+/** 'P4' for known positions, '—' when unknown. */
+export function formatPosition(pos: number | null): string {
+  return pos != null && pos > 0 ? `P${pos}` : '—'
+}
+
+/** '+3' (gained), '−2' (lost), '=' (held), '—' (unknown). */
+export function formatDelta(delta: number | null): string {
+  if (delta == null) return '—'
+  if (delta > 0) return `+${delta}`
+  if (delta < 0) return `−${Math.abs(delta)}`
+  return '='
+}

frontend/src/lib/gpIdentity.ts

@@ -47,7 +47,9 @@ export function countryDecal(meeting: Meeting | undefined | null): string {
   return name.slice(0, 3).toUpperCase() || '—'
 }
 
-export function countryFlag(meeting: Meeting | undefined | null): string {
+export function countryFlag(
+  meeting: Pick<Meeting, 'country_code' | 'country_flag'> | undefined | null,
+): string {
   if (meeting?.country_flag && !/^https?:\/\//i.test(meeting.country_flag)) return meeting.country_flag
   const code = meeting?.country_code?.toUpperCase()
   const iso2 = code ? CODE3_TO_2[code] : ''

frontend/src/lib/h2h.ts

@@ -0,0 +1,47 @@
+import type { ChampHubDriver } from '../types'
+
+export interface TeammatePair {
+  teamName: string
+  teamColour: string
+  driverA: ChampHubDriver
+  driverB: ChampHubDriver
+  /** Drivers on the team beyond the top two (shown as +N). */
+  extraCount: number
+  /** Absolute win gap — smaller means a closer battle. */
+  closeness: number
+}
+
+/** Pair teammates per team for H2H display; skip single-driver teams. */
+export function teammatePairs(drivers: ReadonlyArray<ChampHubDriver>): TeammatePair[] {
+  const byTeam = new Map<string, ChampHubDriver[]>()
+  for (const d of drivers) {
+    const list = byTeam.get(d.team_name) ?? []
+    list.push(d)
+    byTeam.set(d.team_name, list)
+  }
+
+  const pairs: TeammatePair[] = []
+  for (const [teamName, members] of byTeam) {
+    if (members.length < 2) continue
+
+    const sorted = [...members].sort((a, b) => b.points - a.points)
+    const driverA = sorted[0]
+    const driverB = sorted[1]
+    const winsA = driverA.teammate_wins
+    const winsB = driverB.teammate_wins
+
+    pairs.push({
+      teamName,
+      teamColour: driverA.team_colour,
+      driverA,
+      driverB,
+      extraCount: members.length - 2,
+      closeness: Math.abs(winsA - winsB),
+    })
+  }
+
+  return pairs.sort((a, b) => {
+    if (a.closeness !== b.closeness) return a.closeness - b.closeness
+    return a.teamName.localeCompare(b.teamName)
+  })
+}

frontend/src/lib/preview.ts

@@ -0,0 +1,123 @@
+import type { ChampionshipHub, EnrichedGrid, EnrichedResult, Meeting, Session } from '../types'
+import {
+  currentAndNextSession,
+  nextUpcomingMeeting,
+  sessionStartTime,
+  sortSessionsByStart,
+} from './schedule'
+
+export const RACE_WIN_POINTS = 25
+export const SPRINT_WIN_POINTS = 8
+export const SPRINT_WEEKEND_MAX_POINTS = RACE_WIN_POINTS + SPRINT_WIN_POINTS
+
+export function pickPreviewMeeting(meetings: Meeting[], now: Date): Meeting | null {
+  const active = meetings.filter((m) => !m.is_cancelled)
+  return nextUpcomingMeeting(active, now)
+}
+
+export function findPriorYearMeetingByCircuit(
+  priorYearMeetings: Meeting[],
+  circuitKey: number | undefined,
+): Meeting | null {
+  if (!circuitKey) return null
+  return priorYearMeetings.find((m) => m.circuit_key === circuitKey && !m.is_cancelled) ?? null
+}
+
+export function findRaceSession(sessions: Session[]): Session | null {
+  const sorted = sortSessionsByStart(sessions)
+  return (
+    sorted.find((s) => {
+      const type = s.session_type?.toLowerCase() ?? ''
+      return type.includes('race') && !type.includes('sprint')
+    }) ?? null
+  )
+}
+
+export function isSprintWeekend(sessions: Session[]): boolean {
+  return sessions.some((s) => {
+    const label = `${s.session_type} ${s.session_name}`.toLowerCase()
+    return /\bsprint\b/.test(label) && !label.includes('sprint qualifying') && !label.includes('sprint shootout')
+  })
+}
+
+export interface PodiumPlace {
+  position: number
+  name_acronym: string
+  full_name: string
+  team_name: string
+  team_colour: string
+}
+
+export interface PolePosition {
+  name_acronym: string
+  full_name: string
+  team_name: string
+  team_colour: string
+}
+
+export function extractPodium(results: EnrichedResult[]): PodiumPlace[] {
+  return results
+    .filter((r) => r.position >= 1 && r.position <= 3 && !r.dns && !r.dsq)
+    .sort((a, b) => a.position - b.position)
+    .map((r) => ({
+      position: r.position,
+      name_acronym: r.name_acronym,
+      full_name: r.full_name,
+      team_name: r.team_name,
+      team_colour: r.team_colour,
+    }))
+}
+
+export function extractPole(grid: EnrichedGrid[]): PolePosition | null {
+  const pole = grid.find((g) => g.position === 1)
+  if (!pole) return null
+  return {
+    name_acronym: pole.name_acronym,
+    full_name: pole.full_name,
+    team_name: pole.team_name,
+    team_colour: pole.team_colour,
+  }
+}
+
+export interface TitleFightDriver {
+  name_acronym: string
+  full_name: string
+  team_colour: string
+  points: number
+  position: number
+  gapToLeader: number
+  gapAfterRaceWin: number
+  gapAfterSprintWeekendMax: number
+}
+
+export function buildTitleFightContext(hub: ChampionshipHub): TitleFightDriver[] {
+  if (hub.drivers.length === 0) return []
+  const leader = hub.drivers[0]
+  return hub.drivers.slice(0, 3).map((d) => ({
+    name_acronym: d.name_acronym,
+    full_name: d.full_name,
+    team_colour: d.team_colour,
+    points: d.points,
+    position: d.position,
+    gapToLeader: leader.points - d.points,
+    gapAfterRaceWin: leader.points - (d.points + RACE_WIN_POINTS),
+    gapAfterSprintWeekendMax: leader.points - (d.points + SPRINT_WEEKEND_MAX_POINTS),
+  }))
+}
+
+export function countdownTargetSession(sessions: Session[], now: Date): Session | null {
+  const sorted = sortSessionsByStart(sessions)
+  const { next } = currentAndNextSession(sorted, now)
+  if (next) return next
+  for (const session of sorted) {
+    const start = sessionStartTime(session)
+    if (start && start > now) return session
+  }
+  return null
+}
+
+export function formatPointsGap(gap: number): string {
+  if (gap === 0) return 'LEADER'
+  const sign = gap > 0 ? '+' : ''
+  return `${sign}${Number.isInteger(gap) ? gap : gap.toFixed(1)}`
+}

frontend/src/lib/replay.ts

@@ -0,0 +1,75 @@
+import type { ReplayCarPosition, ReplayFrame, TrackBounds } from '../types'
+import { canvasToSvg, normalizeRawPoint } from './trackmap'
+
+export interface ReplayFramePair {
+  previous: ReplayFrame | null
+  next: ReplayFrame | null
+}
+
+export function lookupReplayFramePair(
+  frames: ReadonlyArray<ReplayFrame>,
+  tMs: number,
+): ReplayFramePair {
+  if (frames.length === 0) return { previous: null, next: null }
+  if (tMs <= frames[0].t) return { previous: frames[0], next: frames[0] }
+  const last = frames[frames.length - 1]
+  if (tMs >= last.t) return { previous: last, next: last }
+
+  let lo = 0
+  let hi = frames.length - 1
+  while (lo <= hi) {
+    const mid = Math.floor((lo + hi) / 2)
+    const frame = frames[mid]
+    if (frame.t === tMs) return { previous: frame, next: frame }
+    if (frame.t < tMs) {
+      lo = mid + 1
+    } else {
+      hi = mid - 1
+    }
+  }
+
+  return { previous: frames[Math.max(0, hi)], next: frames[Math.min(frames.length - 1, lo)] }
+}
+
+export function interpolateReplayCars(
+  frames: ReadonlyArray<ReplayFrame>,
+  tMs: number,
+): Record<string, ReplayCarPosition> {
+  const { previous, next } = lookupReplayFramePair(frames, tMs)
+  if (!previous && !next) return {}
+  if (!previous) return next?.cars ?? {}
+  if (!next || previous.t === next.t) return previous.cars
+
+  const span = next.t - previous.t
+  const fraction = span <= 0 ? 0 : clamp01((tMs - previous.t) / span)
+  const cars: Record<string, ReplayCarPosition> = {}
+  const numbers = new Set([...Object.keys(previous.cars), ...Object.keys(next.cars)])
+
+  for (const number of numbers) {
+    const before = previous.cars[number]
+    const after = next.cars[number]
+    if (before && after) {
+      cars[number] = {
+        x: before.x + (after.x - before.x) * fraction,
+        y: before.y + (after.y - before.y) * fraction,
+      }
+    } else if (before) {
+      cars[number] = before
+    } else if (after) {
+      cars[number] = after
+    }
+  }
+  return cars
+}
+
+export function replayCarToSvg(
+  car: ReplayCarPosition,
+  bounds: TrackBounds,
+): ReplayCarPosition {
+  return canvasToSvg(normalizeRawPoint({ x: car.x, y: car.y }, bounds))
+}
+
+function clamp01(value: number): number {
+  if (!Number.isFinite(value)) return 0
+  return Math.min(1, Math.max(0, value))
+}

frontend/src/lib/rivalry.ts

@@ -0,0 +1,61 @@
+// Pure helpers for the championship rivalry compare view.
+
+/** One round that counted toward the head-to-head tally. */
+export interface H2HRound {
+  round: number // 1-based season round
+  label: string
+  posA: number
+  posB: number
+  winner: 'a' | 'b'
+}
+
+export interface H2HTally {
+  a: number
+  b: number
+  /** Rounds counted in the tally, in season order. */
+  rounds: H2HRound[]
+  /** Rounds skipped because either driver had no finishing position. */
+  skipped: number
+}
+
+/**
+ * Per-round points gap (a − b) across the rounds both cumulative series
+ * cover. Positive values mean driver A is ahead.
+ */
+export function gapSeries(a: number[], b: number[]): number[] {
+  const n = Math.min(a.length, b.length)
+  const out: number[] = []
+  for (let i = 0; i < n; i++) out.push(a[i] - b[i])
+  return out
+}
+
+/**
+ * Race head-to-head: per round, the lower finishing position wins. Rounds
+ * where either driver has no position (0 / missing) are skipped from the
+ * tally, as are equal positions (defensive — races can't tie).
+ */
+export function h2hTally(posA: number[], posB: number[], labels: string[]): H2HTally {
+  const n = Math.max(posA.length, posB.length)
+  const rounds: H2HRound[] = []
+  let a = 0
+  let b = 0
+  let skipped = 0
+  for (let i = 0; i < n; i++) {
+    const pa = posA[i] ?? 0
+    const pb = posB[i] ?? 0
+    if (pa <= 0 || pb <= 0 || pa === pb) {
+      skipped++
+      continue
+    }
+    const winner = pa < pb ? 'a' : 'b'
+    if (winner === 'a') a++
+    else b++
+    rounds.push({ round: i + 1, label: labels[i] ?? `R${i + 1}`, posA: pa, posB: pb, winner })
+  }
+  return { a, b, rounds, skipped }
+}
+
+/** Last n counted rounds of a tally, for the mini strip. */
+export function lastRounds(tally: H2HTally, n: number): H2HRound[] {
+  return tally.rounds.slice(-n)
+}

frontend/src/pages/BriefingPage.tsx

@@ -1,13 +1,33 @@
-import { useCallback, useEffect, useRef, useState } from 'react'
+import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import { useQuery, useQueryClient } from '@tanstack/react-query'
-import { fetchNews, fetchNewsArticle, markNewsRead } from '../api'
+import {
+  fetchChampionshipHub,
+  fetchNews,
+  fetchNewsArticle,
+  fetchSeasonMeetings,
+  fetchSeasons,
+  markNewsRead,
+} from '../api'
+import {
+  activeDigestWindow,
+  filterByTag,
+  groupByWindow,
+  gpWindows,
+  itemsForWindow,
+  sinceLastLabel,
+  sortWindowBucketsNewestFirst,
+  tagColour,
+  tagItems,
+  topTags,
+  type DigestTag,
+  type TaggedNewsItem,
+} from '../lib/digest'
 import { stripHtml, timeAgo } from '../utils'
 import type { ArticleContent, NewsItem } from '../types'
+import '../styles/digest.css'
 
 type Category = 'all' | 'official' | 'news' | 'video'
 
-const PAGE_SIZE = 16
-
 const CATEGORY_LABELS: Record<Category, string> = {
   all: 'All',
   official: 'Official',
@@ -71,6 +91,31 @@ function CategoryTabs({
   )
 }
 
+function TagChip({
+  tag,
+  active,
+  onClick,
+  className = 'digest-tag-chip',
+}: {
+  tag: DigestTag
+  active?: boolean
+  onClick?: () => void
+  className?: string
+}) {
+  return (
+    <button
+      type="button"
+      className={`${className}${active ? ' active' : ''}`}
+      style={{ '--tag-colour': tagColour(tag.colour) } as React.CSSProperties}
+      onClick={onClick}
+      aria-pressed={active}
+    >
+      <span className="digest-tag-dot" aria-hidden="true" />
+      {tag.label}
+    </button>
+  )
+}
+
 function OGImage({ url, title }: { url?: string; title: string }) {
   const [failed, setFailed] = useState(false)
   const initial = (title[0] ?? '?').toUpperCase()
@@ -98,11 +143,15 @@ function OGImage({ url, title }: { url?: string; title: string }) {
 function BriefingCard({
   item,
   isActive,
+  activeTag,
   onSelect,
+  onTagClick,
 }: {
-  item: NewsItem
+  item: TaggedNewsItem
   isActive: boolean
+  activeTag: string | null
   onSelect: (item: NewsItem) => void
+  onTagClick: (tag: DigestTag) => void
 }) {
   const isRead = !!item.read_at
   const isVideo = categoryOf(item) === 'video'
@@ -129,6 +178,25 @@ function BriefingCard({
             {stripHtml(item.og_description || item.summary || '')}
           </p>
         )}
+        {item.tags.length > 0 && (
+          <div className="bp-card-tags">
+            {item.tags.map((tag) => (
+              <button
+                key={tag.key}
+                type="button"
+                className={`bp-card-tag${activeTag === tag.key ? ' active' : ''}`}
+                style={{ '--tag-colour': tagColour(tag.colour) } as React.CSSProperties}
+                onClick={(e) => {
+                  e.stopPropagation()
+                  onTagClick(tag)
+                }}
+              >
+                <span className="digest-tag-dot" aria-hidden="true" />
+                {tag.label}
+              </button>
+            ))}
+          </div>
+        )}
       </div>
     </article>
   )
@@ -146,7 +214,6 @@ function ReaderPanel({
   const [loading, setLoading] = useState(false)
   const [error, setError] = useState<string | null>(null)
 
-  // Close on Escape
   useEffect(() => {
     const handler = (e: KeyboardEvent) => {
       if (e.key === 'Escape') onClose()
@@ -155,7 +222,6 @@ function ReaderPanel({
     return () => document.removeEventListener('keydown', handler)
   }, [onClose])
 
-  // Fetch article when item changes
   useEffect(() => {
     if (!item) {
       setArticle(null)
@@ -175,9 +241,14 @@ function ReaderPanel({
       .catch((err) => { setError(String(err)); setLoading(false) })
   }, [item?.url, item ? categoryOf(item) : ''])
 
-  // Scroll panel to top when item changes
   useEffect(() => {
-    panelRef.current?.scrollTo({ top: 0 })
+    const panel = panelRef.current
+    if (!panel) return
+    if (typeof panel.scrollTo === 'function') {
+      panel.scrollTo({ top: 0 })
+    } else {
+      panel.scrollTop = 0
+    }
   }, [item?.url])
 
   const isOpen = item !== null
@@ -297,7 +368,6 @@ function ReaderPanel({
               {article && !loading && article.content && (
                 <div
                   className="bp-reader-body"
-                  // readability strips scripts/iframes; sources are all known news outlets
                   // eslint-disable-next-line react/no-danger
                   dangerouslySetInnerHTML={{ __html: article.content }}
                 />
@@ -332,8 +402,9 @@ function ReaderPanel({
 export function BriefingPage() {
   const [activeCategory, setActiveCategory] = useState<Category>('all')
   const [selectedItem, setSelectedItem] = useState<NewsItem | null>(null)
-  const [page, setPage] = useState(1)
+  const [activeTag, setActiveTag] = useState<string | null>(null)
   const queryClient = useQueryClient()
+  const now = useMemo(() => new Date(), [])
 
   const { data: allNews = [], isLoading, isError } = useQuery({
     queryKey: ['news'],
@@ -341,13 +412,74 @@ export function BriefingPage() {
     staleTime: 60_000,
   })
 
-  const filtered = allNews.filter(
-    (item) => activeCategory === 'all' || categoryOf(item) === activeCategory,
+  const seasonsQuery = useQuery({
+    queryKey: ['seasons'],
+    queryFn: fetchSeasons,
+  })
+  const latestSeason = seasonsQuery.data?.[0] ?? null
+
+  const meetingsQuery = useQuery({
+    queryKey: ['season-meetings', latestSeason],
+    queryFn: () => fetchSeasonMeetings(latestSeason!),
+    enabled: latestSeason != null,
+  })
+
+  const hubQuery = useQuery({
+    queryKey: ['championship-hub', latestSeason],
+    queryFn: () => fetchChampionshipHub(latestSeason!),
+    enabled: latestSeason != null,
+  })
+
+  const meetings = meetingsQuery.data ?? []
+  const hub = hubQuery.data
+
+  const taggedNews = useMemo(
+    () => tagItems(allNews, hub?.drivers ?? [], hub?.teams ?? []),
+    [allNews, hub],
   )
-  const pageCount = Math.max(1, Math.ceil(filtered.length / PAGE_SIZE))
-  const safePage = Math.min(page, pageCount)
-  const pageStart = (safePage - 1) * PAGE_SIZE
-  const pagedItems = filtered.slice(pageStart, pageStart + PAGE_SIZE)
+
+  const categoryFiltered = useMemo(
+    () => taggedNews.filter(
+      (item) => activeCategory === 'all' || categoryOf(item) === activeCategory,
+    ),
+    [taggedNews, activeCategory],
+  )
+
+  const tagFiltered = useMemo(
+    () => filterByTag(categoryFiltered, activeTag),
+    [categoryFiltered, activeTag],
+  )
+
+  const windows = useMemo(() => gpWindows(meetings, now), [meetings, now])
+  const grouped = useMemo(() => groupByWindow(tagFiltered, windows), [tagFiltered, windows])
+  const windowSections = useMemo(
+    () => sortWindowBucketsNewestFirst(grouped.windows),
+    [grouped.windows],
+  )
+
+  const activeWindow = useMemo(
+    () => activeDigestWindow(windows, meetings, now),
+    [windows, meetings, now],
+  )
+
+  const sinceLastItems = useMemo(
+    () => itemsForWindow(tagFiltered, activeWindow),
+    [tagFiltered, activeWindow],
+  )
+
+  const sinceLastTags = useMemo(() => topTags(sinceLastItems), [sinceLastItems])
+  const sinceLabel = sinceLastLabel(meetings, now)
+
+  const taggedByUrl = useMemo(() => {
+    const map = new Map<string, TaggedNewsItem>()
+    for (const item of tagFiltered) map.set(item.url, item)
+    return map
+  }, [tagFiltered])
+
+  const recentTagged = useMemo(() => {
+    const urls = new Set(grouped.recent.map((item) => item.url))
+    return tagFiltered.filter((item) => urls.has(item.url))
+  }, [grouped.recent, tagFiltered])
 
   const counts: Record<Category, number> = {
     all: allNews.length,
@@ -374,22 +506,14 @@ export function BriefingPage() {
 
   const handleClose = useCallback(() => setSelectedItem(null), [])
 
-  useEffect(() => {
-    setPage((current) => Math.min(current, pageCount))
-  }, [pageCount])
-
-  const handlePageChange = useCallback(
-    (nextPage: number) => {
-      setPage(Math.min(Math.max(nextPage, 1), pageCount))
-      setSelectedItem(null)
-      window.scrollTo({ top: 0, behavior: 'smooth' })
-    },
-    [pageCount],
-  )
+  const handleTagClick = useCallback((tag: DigestTag) => {
+    setActiveTag((current) => (current === tag.key ? null : tag.key))
+    setSelectedItem(null)
+  }, [])
 
   const unreadCount = allNews.filter((i) => !i.read_at).length
-  const pageEnd = Math.min(pageStart + pagedItems.length, filtered.length)
-  const showPagination = filtered.length > PAGE_SIZE
+  const hasDigest = meetings.length > 0
+  const showEmpty = tagFiltered.length === 0 && grouped.recent.length === 0
 
   return (
     <div className="bp-page" data-testid="briefing-page">
@@ -408,74 +532,106 @@ export function BriefingPage() {
           <CategoryTabs
             active={activeCategory}
             counts={counts}
-            onChange={(c) => { setActiveCategory(c); setSelectedItem(null); setPage(1) }}
+            onChange={(c) => {
+              setActiveCategory(c)
+              setSelectedItem(null)
+              setActiveTag(null)
+            }}
           />
 
-          {filtered.length === 0 ? (
+          {hasDigest && (
+            <div className="digest-sticky" data-testid="digest-sticky-header">
+              <div className="digest-sticky-head">
+                <h2 className="digest-sticky-title">Since {sinceLabel}</h2>
+                <span className="digest-sticky-count">
+                  {sinceLastItems.length} item{sinceLastItems.length === 1 ? '' : 's'}
+                </span>
+              </div>
+              {(sinceLastTags.length > 0 || activeTag) && (
+                <div className="digest-sticky-tags">
+                  {sinceLastTags.map((tag) => (
+                    <TagChip
+                      key={tag.key}
+                      tag={tag}
+                      active={activeTag === tag.key}
+                      onClick={() => handleTagClick(tag)}
+                    />
+                  ))}
+                  {activeTag && (
+                    <button
+                      type="button"
+                      className="digest-filter-clear"
+                      onClick={() => setActiveTag(null)}
+                      data-testid="digest-filter-clear"
+                    >
+                      Clear filter
+                    </button>
+                  )}
+                </div>
+              )}
+            </div>
+          )}
+
+          {showEmpty ? (
             <div className="bp-empty">
               No {activeCategory !== 'all' ? activeCategory : ''} items available.
-              Run <code>box-box --ingest-news</code> to refresh feeds.
+              {activeTag ? ' Try clearing the tag filter.' : ''}
+              {!activeTag && (
+                <>
+                  {' '}
+                  Run <code>box-box --ingest-news</code> to refresh feeds.
+                </>
+              )}
             </div>
           ) : (
             <>
-              {showPagination && (
-                <div className="bp-pagination bp-pagination-top">
-                  <span className="bp-pagination-meta mono">
-                    {pageStart + 1}-{pageEnd} of {filtered.length}
-                  </span>
-                  <div className="bp-pagination-actions">
-                    <button
-                      className="bp-page-btn"
-                      onClick={() => handlePageChange(safePage - 1)}
-                      disabled={safePage === 1}
-                    >
-                      Previous
-                    </button>
-                    <span className="bp-page-current mono">
-                      Page {safePage} / {pageCount}
-                    </span>
-                    <button
-                      className="bp-page-btn"
-                      onClick={() => handlePageChange(safePage + 1)}
-                      disabled={safePage === pageCount}
-                    >
-                      Next
-                    </button>
+              {windowSections.map(({ window, items }) => (
+                <section
+                  key={window.meeting_key}
+                  className="digest-section"
+                  data-testid={`digest-window-${window.meeting_key}`}
+                >
+                  <div className="digest-section-head">
+                    <h3 className="digest-section-title">{window.meeting_name}</h3>
+                    <span className="digest-section-count">{items.length}</span>
                   </div>
-                </div>
-              )}
+                  <div className={`bp-grid${selectedItem ? ' bp-grid-narrow' : ''}`}>
+                    {items.map((item) => {
+                      const tagged = taggedByUrl.get(item.url) ?? { ...item, tags: [] }
+                      return (
+                        <BriefingCard
+                          key={item.url}
+                          item={tagged}
+                          isActive={selectedItem?.url === item.url}
+                          activeTag={activeTag}
+                          onSelect={handleSelect}
+                          onTagClick={handleTagClick}
+                        />
+                      )
+                    })}
+                  </div>
+                </section>
+              ))}
 
-              <div className={`bp-grid${selectedItem ? ' bp-grid-narrow' : ''}`}>
-                {pagedItems.map((item) => (
-                  <BriefingCard
-                    key={item.url}
-                    item={item}
-                    isActive={selectedItem?.url === item.url}
-                    onSelect={handleSelect}
-                  />
-                ))}
-              </div>
-
-              {showPagination && (
-                <div className="bp-pagination bp-pagination-bottom">
-                  <button
-                    className="bp-page-btn"
-                    onClick={() => handlePageChange(safePage - 1)}
-                    disabled={safePage === 1}
-                  >
-                    Previous
-                  </button>
-                  <span className="bp-page-current mono">
-                    Page {safePage} / {pageCount}
-                  </span>
-                  <button
-                    className="bp-page-btn"
-                    onClick={() => handlePageChange(safePage + 1)}
-                    disabled={safePage === pageCount}
-                  >
-                    Next
-                  </button>
-                </div>
+              {recentTagged.length > 0 && (
+                <section className="digest-section digest-recent-section" data-testid="digest-recent">
+                  <div className="digest-section-head">
+                    <h3 className="digest-section-title">Recent</h3>
+                    <span className="digest-section-count">{recentTagged.length}</span>
+                  </div>
+                  <div className={`bp-grid${selectedItem ? ' bp-grid-narrow' : ''}`}>
+                    {recentTagged.map((item) => (
+                      <BriefingCard
+                        key={item.url}
+                        item={item}
+                        isActive={selectedItem?.url === item.url}
+                        activeTag={activeTag}
+                        onSelect={handleSelect}
+                        onTagClick={handleTagClick}
+                      />
+                    ))}
+                  </div>
+                </section>
               )}
             </>
           )}

frontend/src/pages/ChampionshipPage.tsx

@@ -1,13 +1,17 @@
 import { useMemo, useState } from 'react'
 import { useQuery } from '@tanstack/react-query'
+import { Link } from '@tanstack/react-router'
 import { fetchChampionshipHub, fetchSeasons } from '../api'
 import { teamColor } from '../utils'
 import type { ChampHubDriver, ChampionshipHub } from '../types'
 import { ChampionshipSimulator } from '../components/ChampionshipSimulator'
+import { RivalryCompare } from '../components/RivalryCompare'
 import { Meaning } from '../components/Meaning'
+import { TeammateH2H } from '../components/TeammateH2H'
+import { teammatePairs } from '../lib/h2h'
 import { pointsGapMeaning } from '../lib/meaning'
 
-type View = 'drivers' | 'constructors' | 'progression' | 'simulator'
+type View = 'drivers' | 'constructors' | 'progression' | 'rivalry' | 'simulator'
 
 const GOLD = '#ffd700'
 const SILVER = '#c0c0c0'
@@ -213,6 +217,14 @@ function ChampionshipBody({ hub, view, setView }: BodyProps) {
           >
             Progression
           </button>
+          <button
+            type="button"
+            className={`champ-tab${view === 'rivalry' ? ' is-active' : ''}`}
+            onClick={() => setView('rivalry')}
+            data-testid="champ-tab-rivalry"
+          >
+            Rivalry
+          </button>
           <button
             type="button"
             className={`champ-tab${view === 'simulator' ? ' is-active' : ''}`}
@@ -242,10 +254,13 @@ function ChampionshipBody({ hub, view, setView }: BodyProps) {
           leaderPoints={leader.points}
           titleMath={titleMath}
           roundsLeft={hub.rounds_left}
+          drivers={drivers}
+          season={hub.season}
         />
       )}
       {view === 'constructors' && <ConstructorsView hub={hub} />}
       {view === 'progression' && <ProgressionView hub={hub} />}
+      {view === 'rivalry' && <RivalryCompare hub={hub} />}
       {view === 'simulator' && <ChampionshipSimulator hub={hub} />}
     </div>
   )
@@ -271,13 +286,19 @@ function DriversView({
   leaderPoints,
   titleMath,
   roundsLeft,
+  drivers,
+  season,
 }: {
   enriched: EnrichedDriver[]
   leaderPoints: number
   titleMath: string
   roundsLeft: number
+  drivers: ChampHubDriver[]
+  season: number
 }) {
   const podium = enriched.slice(0, 3)
+  const h2hPairs = useMemo(() => teammatePairs(drivers), [drivers])
+
   return (
     <div data-testid="champ-view-drivers">
       <div className="champ-podium">
@@ -336,6 +357,29 @@ function DriversView({
         <span className="champ-titlemath-text">{titleMath}</span>
       </div>
 
+      {h2hPairs.length > 0 && (
+        <section className="h2h-section" data-testid="champ-teammate-battles">
+          <div className="h2h-section-head">
+            <h2 className="h2h-section-title">Teammate battles</h2>
+            <span className="h2h-section-sub">race finishes · closest first</span>
+          </div>
+          <div className="h2h-list">
+            {h2hPairs.map((pair) => (
+              <TeammateH2H
+                key={pair.teamName}
+                teamName={pair.teamName}
+                teamColour={pair.teamColour}
+                driverATla={pair.driverA.name_acronym}
+                driverBTla={pair.driverB.name_acronym}
+                winsA={pair.driverA.teammate_wins}
+                winsB={pair.driverB.teammate_wins}
+                extraNote={pair.extraCount > 0 ? `+${pair.extraCount}` : undefined}
+              />
+            ))}
+          </div>
+        </section>
+      )}
+
       <div className="champ-scroll">
         <table className="champ-table champ-table-drivers">
           <thead>
@@ -360,12 +404,19 @@ function DriversView({
                   P{e.pos}
                 </td>
                 <td>
-                  <div className="champ-drv">
+                  <Link
+                    to="/drivers/$driverNumber"
+                    params={{ driverNumber: String(e.d.driver_number) }}
+                    search={{ year: season }}
+                    className="champ-drv"
+                    style={{ color: 'inherit', textDecoration: 'none' }}
+                    data-testid={`champ-driver-link-${e.d.driver_number}`}
+                  >
                     <span className="champ-drv-bar" style={{ background: e.color }} />
                     <span className="champ-drv-code mono">{e.d.name_acronym}</span>
                     <span className="champ-drv-name">{e.d.full_name}</span>
                     <span className="champ-drv-num mono">#{e.d.driver_number}</span>
-                  </div>
+                  </Link>
                 </td>
                 <td className="champ-td-team">{e.d.team_name}</td>
                 <td className="r mono champ-td-pts">{fmtPts(e.d.points)}</td>

frontend/src/pages/DriverProfilePage.tsx

@@ -0,0 +1,369 @@
+import { useQuery } from '@tanstack/react-query'
+import { Link } from '@tanstack/react-router'
+import { fetchDriverSummary, fetchSeasons } from '../api'
+import { teamColor } from '../utils'
+import { countryFlag } from '../lib/gpIdentity'
+import {
+  formatDelta,
+  formatPosition,
+  gridFinishDeltas,
+  type RoundDelta,
+} from '../lib/driverProfile'
+import type { DriverSummary } from '../types'
+import '../styles/driver-profile.css'
+
+interface Props {
+  driverNumber: number
+  year?: number
+}
+
+function fmtPts(n: number): string {
+  return Number.isInteger(n) ? String(n) : n.toFixed(1)
+}
+
+export function DriverProfilePage({ driverNumber, year }: Props) {
+  // Without an explicit ?year=, default to the latest ingested season; if the
+  // seasons list is empty/unavailable the backend falls back to the current year.
+  const seasonsQuery = useQuery({
+    queryKey: ['seasons'],
+    queryFn: fetchSeasons,
+    enabled: year == null,
+  })
+  const resolvedYear = year ?? seasonsQuery.data?.[0]
+  const seasonsSettled = year != null || !seasonsQuery.isLoading
+
+  const summaryQuery = useQuery({
+    queryKey: ['driver-summary', driverNumber, resolvedYear ?? 'latest'],
+    queryFn: () => fetchDriverSummary(driverNumber, resolvedYear),
+    enabled: seasonsSettled && driverNumber > 0,
+    staleTime: 5 * 60_000,
+  })
+
+  if (driverNumber <= 0) {
+    return <div className="page error-box">Invalid driver number</div>
+  }
+  if (!seasonsSettled || summaryQuery.isLoading) {
+    return <div className="page loading-state">loading driver profile…</div>
+  }
+  if (summaryQuery.isError) {
+    return (
+      <div className="page error-box">
+        {summaryQuery.error instanceof Error
+          ? summaryQuery.error.message
+          : 'Failed to load driver profile'}
+      </div>
+    )
+  }
+  const summary = summaryQuery.data
+  if (!summary) {
+    return <div className="page error-box">No driver data</div>
+  }
+  return <DriverProfileBody summary={summary} />
+}
+
+function DriverProfileBody({ summary }: { summary: DriverSummary }) {
+  const color = teamColor(summary.team_colour)
+  const deltas = gridFinishDeltas(summary.rounds)
+
+  return (
+    <div className="dp-page" data-testid="driver-profile">
+      <header className="dp-header" data-testid="dp-header" style={{ borderLeftColor: color }}>
+        <div className="dp-identity">
+          <div className="dp-title-row">
+            <span className="dp-code mono">{summary.name_acronym || `#${summary.driver_number}`}</span>
+            <span className="dp-num mono" style={{ color }}>
+              #{summary.driver_number}
+            </span>
+          </div>
+          <h1 className="dp-name">{summary.full_name || `Driver ${summary.driver_number}`}</h1>
+          <div className="dp-team">
+            <span className="dp-team-swatch" style={{ background: color }} />
+            {summary.team_name || 'Unknown team'}
+            <span className="dp-season mono">{summary.season}</span>
+          </div>
+        </div>
+        <div className="dp-stat-rail">
+          <div className="dp-stat">
+            <div className="dp-stat-value mono">{summary.position > 0 ? `P${summary.position}` : '—'}</div>
+            <div className="dp-stat-label">Championship</div>
+          </div>
+          <div className="dp-stat">
+            <div className="dp-stat-value mono">{fmtPts(summary.points)}</div>
+            <div className="dp-stat-label">Points</div>
+          </div>
+          <div className="dp-stat">
+            <div className="dp-stat-value mono">{summary.wins}</div>
+            <div className="dp-stat-label">Wins</div>
+          </div>
+          <div className="dp-stat">
+            <div className="dp-stat-value mono">{summary.podiums}</div>
+            <div className="dp-stat-label">Podiums</div>
+          </div>
+          <div className="dp-stat">
+            <div className="dp-stat-value mono">{summary.poles}</div>
+            <div className="dp-stat-label">Poles</div>
+          </div>
+        </div>
+        <Link to="/championship" className="dp-back mono">
+          ← Championship
+        </Link>
+      </header>
+
+      <section className="dp-section" data-testid="dp-form">
+        <h2 className="dp-section-title mono">Season form</h2>
+        {summary.cumulative.length > 0 ? (
+          <div className="dp-form-grid">
+            <CumulativeLine
+              cumulative={summary.cumulative}
+              labels={summary.round_labels}
+              color={color}
+            />
+            <FormStrip form={summary.form} color={color} />
+          </div>
+        ) : (
+          <div className="dp-empty">No completed rounds yet.</div>
+        )}
+      </section>
+
+      <section className="dp-section" data-testid="dp-quali-race">
+        <h2 className="dp-section-title mono">Quali vs race</h2>
+        {deltas.some((d) => d.delta != null) ? (
+          <GridVsRaceChart deltas={deltas} color={color} />
+        ) : (
+          <div className="dp-empty">No grid-vs-finish data yet.</div>
+        )}
+      </section>
+
+      <section className="dp-section" data-testid="dp-rounds">
+        <h2 className="dp-section-title mono">Track by track</h2>
+        {summary.rounds.length > 0 ? (
+          <RoundsTable summary={summary} deltas={deltas} />
+        ) : (
+          <div className="dp-empty">No completed rounds yet.</div>
+        )}
+      </section>
+    </div>
+  )
+}
+
+const LINE_W = 640
+const LINE_H = 180
+const LINE_PL = 44
+const LINE_PR = 16
+const LINE_PT = 12
+const LINE_PB = 24
+
+function CumulativeLine({
+  cumulative,
+  labels,
+  color,
+}: {
+  cumulative: number[]
+  labels: string[]
+  color: string
+}) {
+  const n = cumulative.length
+  const maxY = Math.max(25, ...cumulative)
+  const plotW = LINE_W - LINE_PL - LINE_PR
+  const plotH = LINE_H - LINE_PT - LINE_PB
+  const x = (i: number) => (n <= 1 ? LINE_PL + plotW / 2 : LINE_PL + (i * plotW) / (n - 1))
+  const y = (v: number) => LINE_PT + plotH - (v / maxY) * plotH
+  const points = cumulative.map((v, i) => `${x(i).toFixed(1)},${y(v).toFixed(1)}`).join(' ')
+
+  const tickStep = Math.max(1, Math.ceil(n / 8))
+  const ticks: { x: number; label: string }[] = []
+  for (let i = 0; i < n; i += tickStep) {
+    ticks.push({ x: x(i), label: labels[i] ?? `R${i + 1}` })
+  }
+
+  return (
+    <figure className="dp-chart">
+      <figcaption className="dp-chart-caption mono">Cumulative points</figcaption>
+      <svg viewBox={`0 0 ${LINE_W} ${LINE_H}`} className="dp-chart-svg" role="img" aria-label="Cumulative points per round">
+        {[0, 0.5, 1].map((f) => {
+          const v = Math.round(maxY * f)
+          return (
+            <g key={f}>
+              <line x1={LINE_PL} y1={y(v)} x2={LINE_W - LINE_PR} y2={y(v)} className="dp-gridline" />
+              <text x={LINE_PL - 6} y={y(v) + 3} textAnchor="end" className="dp-axis">
+                {v}
+              </text>
+            </g>
+          )
+        })}
+        {ticks.map((t) => (
+          <text key={t.label} x={t.x} y={LINE_H - 8} textAnchor="middle" className="dp-axis">
+            {t.label}
+          </text>
+        ))}
+        <polyline
+          points={points}
+          fill="none"
+          stroke={color}
+          strokeWidth="2.2"
+          strokeLinejoin="round"
+          strokeLinecap="round"
+        />
+        <circle cx={x(n - 1)} cy={y(cumulative[n - 1])} r="3.2" fill={color} />
+      </svg>
+    </figure>
+  )
+}
+
+function FormStrip({ form, color }: { form: number[]; color: string }) {
+  const max = Math.max(25, ...form)
+  return (
+    <div className="dp-form-strip">
+      <div className="dp-chart-caption mono">Last {form.length} races</div>
+      <div className="dp-form-bars">
+        {form.map((pts, i) => (
+          <div className="dp-form-bar" key={i} title={`${fmtPts(pts)} pts`}>
+            <div
+              className="dp-form-bar-fill"
+              style={{ height: `${Math.max(4, (pts / max) * 100)}%`, background: color }}
+            />
+            <span className="dp-form-bar-val mono">{fmtPts(pts)}</span>
+          </div>
+        ))}
+      </div>
+    </div>
+  )
+}
+
+const DELTA_H = 190
+const DELTA_PT = 14
+const DELTA_PB = 30
+
+function GridVsRaceChart({ deltas, color }: { deltas: RoundDelta[]; color: string }) {
+  const maxAbs = Math.max(1, ...deltas.map((d) => Math.abs(d.delta ?? 0)))
+  const colW = 34
+  const w = Math.max(240, deltas.length * colW)
+  const plotH = DELTA_H - DELTA_PT - DELTA_PB
+  const zeroY = DELTA_PT + plotH / 2
+  const scale = plotH / 2 / maxAbs
+
+  return (
+    <figure className="dp-chart">
+      <figcaption className="dp-chart-caption mono">
+        Positions gained (▲) / lost (▼) from grid to flag, per round
+      </figcaption>
+      <div className="dp-chart-scroll">
+        <svg
+          viewBox={`0 0 ${w} ${DELTA_H}`}
+          width={w}
+          height={DELTA_H}
+          className="dp-delta-svg"
+          role="img"
+          aria-label="Positions gained or lost per round"
+        >
+          <line x1={0} y1={zeroY} x2={w} y2={zeroY} className="dp-zeroline" />
+          {deltas.map((d, i) => {
+            const cx = i * colW + colW / 2
+            if (d.delta == null) {
+              return (
+                <g key={d.round}>
+                  <text x={cx} y={zeroY - 6} textAnchor="middle" className="dp-axis">
+                    ·
+                  </text>
+                  <text x={cx} y={DELTA_H - 8} textAnchor="middle" className="dp-axis">
+                    R{d.round}
+                  </text>
+                </g>
+              )
+            }
+            const h = Math.abs(d.delta) * scale
+            const yTop = d.delta >= 0 ? zeroY - h : zeroY
+            return (
+              <g key={d.round}>
+                <title>{`${d.label}: ${formatPosition(d.grid)} → ${formatPosition(d.finish)} (${formatDelta(d.delta)})`}</title>
+                <rect
+                  x={cx - 8}
+                  y={yTop}
+                  width={16}
+                  height={Math.max(1.5, h)}
+                  rx={2}
+                  fill={color}
+                  opacity={d.delta >= 0 ? 0.95 : 0.45}
+                />
+                <text
+                  x={cx}
+                  y={d.delta >= 0 ? yTop - 4 : yTop + h + 11}
+                  textAnchor="middle"
+                  className="dp-delta-val mono"
+                >
+                  {formatDelta(d.delta)}
+                </text>
+                <text x={cx} y={DELTA_H - 8} textAnchor="middle" className="dp-axis">
+                  R{d.round}
+                </text>
+              </g>
+            )
+          })}
+        </svg>
+      </div>
+    </figure>
+  )
+}
+
+function statusNote(d: RoundDelta): string {
+  if (d.status === 'dnf') return 'DNF'
+  if (d.status === 'dns') return 'DNS'
+  if (d.status === 'dsq') return 'DSQ'
+  if (d.status === 'absent') return '—'
+  return ''
+}
+
+function RoundsTable({ summary, deltas }: { summary: DriverSummary; deltas: RoundDelta[] }) {
+  return (
+    <div className="dp-scroll">
+      <table className="dp-table">
+        <thead>
+          <tr>
+            <th className="l">Rnd</th>
+            <th className="l">Grand Prix</th>
+            <th className="r">Grid</th>
+            <th className="r">Race</th>
+            <th className="r">Δ</th>
+            <th className="r">Pts</th>
+            <th className="l"></th>
+          </tr>
+        </thead>
+        <tbody>
+          {summary.rounds.map((r, i) => {
+            const d = deltas[i]
+            return (
+              <tr key={r.meeting_key}>
+                <td className="mono dp-td-dim">R{i + 1}</td>
+                <td>
+                  <span className="dp-flag" aria-hidden="true">
+                    {countryFlag({ country_code: r.country_code, country_flag: '' })}
+                  </span>
+                  {r.meeting_name}
+                </td>
+                <td className="r mono">{formatPosition(d.grid)}</td>
+                <td className="r mono">{formatPosition(d.finish)}</td>
+                <td
+                  className="r mono"
+                  style={{
+                    color:
+                      d.delta == null
+                        ? 'var(--text-3)'
+                        : d.delta > 0
+                          ? 'var(--green)'
+                          : d.delta < 0
+                            ? 'var(--red)'
+                            : 'var(--text-2)',
+                  }}
+                >
+                  {formatDelta(d.delta)}
+                </td>
+                <td className="r mono">{fmtPts(r.points)}</td>
+                <td className="dp-td-dim mono">{statusNote(d)}</td>
+              </tr>
+            )
+          })}
+        </tbody>
+      </table>
+    </div>
+  )
+}

frontend/src/pages/RacePreviewPage.tsx

@@ -0,0 +1,442 @@
+import { useEffect, useMemo, useState, type ReactNode } from 'react'
+import { useQuery } from '@tanstack/react-query'
+import {
+  fetchChampionshipHub,
+  fetchMeetings,
+  fetchResults,
+  fetchSeasons,
+  fetchSessions,
+  fetchStartingGrid,
+  fetchTrackOutline,
+} from '../api'
+import { countryAccent, countryFlag, formatGpDateRange } from '../lib/gpIdentity'
+import {
+  buildTitleFightContext,
+  countdownTargetSession,
+  extractPodium,
+  extractPole,
+  findPriorYearMeetingByCircuit,
+  findRaceSession,
+  formatPointsGap,
+  isSprintWeekend,
+  pickPreviewMeeting,
+  RACE_WIN_POINTS,
+  SPRINT_WEEKEND_MAX_POINTS,
+} from '../lib/preview'
+import { formatCountdown, formatSessionScheduleTime, sessionStartTime, sortSessionsByStart } from '../lib/schedule'
+import { buildOutlinePath } from '../lib/trackmap'
+import { teamColor } from '../utils'
+import type { Meeting, Session, TrackOutline } from '../types'
+import '../styles/preview.css'
+
+function SectionState({
+  loading,
+  error,
+  empty,
+  emptyMessage,
+  children,
+}: {
+  loading?: boolean
+  error?: Error | null
+  empty?: boolean
+  emptyMessage?: string
+  children: ReactNode
+}) {
+  if (loading) {
+    return <div className="preview-section-state">Loading…</div>
+  }
+  if (error) {
+    return (
+      <div className="preview-section-state error">
+        {error instanceof Error ? error.message : 'Failed to load'}
+      </div>
+    )
+  }
+  if (empty) {
+    return <div className="preview-section-state">{emptyMessage ?? 'No data available'}</div>
+  }
+  return <>{children}</>
+}
+
+function TrackOutlineCard({
+  outline,
+  loading,
+  error,
+  accent,
+}: {
+  outline: TrackOutline | null | undefined
+  loading: boolean
+  error: Error | null
+  accent: string
+}) {
+  const outlinePath = useMemo(() => buildOutlinePath(outline?.points ?? []), [outline])
+
+  return (
+    <section className="preview-card" data-testid="preview-track-card">
+      <h2 className="preview-card-title">Circuit</h2>
+      <SectionState
+        loading={loading}
+        error={error}
+        empty={!outline || !outlinePath}
+        emptyMessage="Track outline unavailable for this circuit"
+      >
+        <div className="preview-track-stage" style={{ ['--preview-accent' as string]: accent }}>
+          <svg className="preview-track-svg" viewBox="0 0 100 100" role="img" aria-label="Circuit outline">
+            <path className="preview-track-shadow" d={outlinePath} />
+            <path className="preview-track-outline" d={outlinePath} />
+          </svg>
+        </div>
+      </SectionState>
+    </section>
+  )
+}
+
+function LastYearCard({
+  year,
+  loading,
+  error,
+  podium,
+  pole,
+  isFirstTime,
+}: {
+  year: number | null
+  loading: boolean
+  error: Error | null
+  podium: ReturnType<typeof extractPodium>
+  pole: ReturnType<typeof extractPole>
+  isFirstTime: boolean
+}) {
+  return (
+    <section className="preview-card" data-testid="preview-last-year-card">
+      <h2 className="preview-card-title">Last year here</h2>
+      {year != null && !isFirstTime && <p className="preview-card-sub">{year} race weekend</p>}
+      <SectionState
+        loading={loading}
+        error={error}
+        empty={isFirstTime || podium.length === 0}
+        emptyMessage={
+          isFirstTime
+            ? 'First time on the calendar — no prior race at this circuit'
+            : 'No race results available for the previous visit'
+        }
+      >
+        <div className="preview-podium">
+          {podium.map((place) => (
+            <div key={place.position} className="preview-podium-row">
+              <span className="preview-podium-pos">P{place.position}</span>
+              <span className="preview-podium-code" style={{ color: teamColor(place.team_colour) }}>
+                {place.name_acronym}
+              </span>
+              <span className="preview-podium-team">{place.team_name}</span>
+            </div>
+          ))}
+        </div>
+        {pole && (
+          <p className="preview-pole">
+            Pole: <strong style={{ color: teamColor(pole.team_colour) }}>{pole.name_acronym}</strong>{' '}
+            ({pole.team_name})
+          </p>
+        )}
+      </SectionState>
+    </section>
+  )
+}
+
+function TitleFightCard({
+  loading,
+  error,
+  drivers,
+  sprintWeekend,
+  season,
+}: {
+  loading: boolean
+  error: Error | null
+  drivers: ReturnType<typeof buildTitleFightContext>
+  sprintWeekend: boolean
+  season: number | null
+}) {
+  return (
+    <section className="preview-card preview-card--wide" data-testid="preview-title-fight-card">
+      <h2 className="preview-card-title">Title fight context</h2>
+      {season != null && <p className="preview-card-sub">{season} drivers&apos; championship · top 3</p>}
+      <SectionState
+        loading={loading}
+        error={error}
+        empty={drivers.length === 0}
+        emptyMessage="Championship standings not available"
+      >
+        <table className="preview-title-table">
+          <thead>
+            <tr>
+              <th>Driver</th>
+              <th>Pts</th>
+              <th>Gap</th>
+              <th>If win (+{RACE_WIN_POINTS})</th>
+            </tr>
+          </thead>
+          <tbody>
+            {drivers.map((d) => (
+              <tr key={d.name_acronym}>
+                <td>
+                  <span style={{ color: teamColor(d.team_colour), fontWeight: 600 }}>{d.name_acronym}</span>
+                </td>
+                <td className="mono">{d.points}</td>
+                <td className="mono">{formatPointsGap(d.gapToLeader)}</td>
+                <td className="mono">
+                  {d.position === 1 ? 'LEADER' : formatPointsGap(d.gapAfterRaceWin)}
+                </td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+        {sprintWeekend && (
+          <p className="preview-sprint-note" data-testid="preview-sprint-note">
+            Sprint weekend: up to {SPRINT_WEEKEND_MAX_POINTS} pts available (race win {RACE_WIN_POINTS} + sprint win
+            8). Max gain would reduce gaps by {SPRINT_WEEKEND_MAX_POINTS} vs a standard race win.
+          </p>
+        )}
+      </SectionState>
+    </section>
+  )
+}
+
+function PreviewHeader({
+  meeting,
+  sessions,
+  countdownSession,
+  now,
+  accent,
+}: {
+  meeting: Meeting
+  sessions: Session[]
+  countdownSession: Session | null
+  now: Date
+  accent: string
+}) {
+  const countdownTarget = countdownSession ? sessionStartTime(countdownSession) : null
+
+  return (
+    <header
+      className="preview-header"
+      data-testid="preview-header"
+      style={{ ['--preview-accent' as string]: accent }}
+    >
+      <div className="preview-header-accent" />
+      <div className="preview-header-body">
+        <div className="preview-header-top">
+          <div>
+            <h1 className="preview-gp-name">
+              {countryFlag(meeting) && <span className="preview-gp-flag">{countryFlag(meeting)}</span>}
+              {meeting.meeting_name}
+            </h1>
+            <p className="preview-circuit">
+              {meeting.circuit_short_name}
+              {meeting.location ? ` · ${meeting.location}` : ''}
+              {formatGpDateRange(meeting) ? ` · ${formatGpDateRange(meeting)}` : ''}
+            </p>
+          </div>
+          {countdownTarget && (
+            <div className="preview-countdown" data-testid="preview-countdown">
+              <span className="preview-countdown-label">
+                {countdownSession?.session_name ?? 'Next session'}
+              </span>
+              <span className="preview-countdown-value">{formatCountdown(countdownTarget, now)}</span>
+            </div>
+          )}
+        </div>
+        {sessions.length > 0 && (
+          <div className="preview-schedule" data-testid="preview-schedule">
+            {sessions.map((session) => (
+              <div key={session.session_key} className="preview-schedule-item">
+                <span className="preview-schedule-name">{session.session_name}</span>
+                <span className="preview-schedule-time">{formatSessionScheduleTime(session.date_start)}</span>
+              </div>
+            ))}
+          </div>
+        )}
+      </div>
+    </header>
+  )
+}
+
+export function RacePreviewPage() {
+  const [now, setNow] = useState(() => Date.now())
+
+  useEffect(() => {
+    const timer = window.setInterval(() => setNow(Date.now()), 1000)
+    return () => window.clearInterval(timer)
+  }, [])
+
+  const nowDate = useMemo(() => new Date(now), [now])
+
+  const seasonsQuery = useQuery({
+    queryKey: ['seasons'],
+    queryFn: fetchSeasons,
+  })
+
+  const latestSeason = seasonsQuery.data?.[0] ?? null
+
+  const meetingsQuery = useQuery({
+    queryKey: ['meetings', latestSeason, 'auto'],
+    queryFn: () => fetchMeetings(latestSeason!, 'auto'),
+    enabled: latestSeason != null,
+  })
+
+  const previewMeeting = useMemo(
+    () => pickPreviewMeeting(meetingsQuery.data ?? [], nowDate),
+    [meetingsQuery.data, nowDate],
+  )
+
+  const sessionsQuery = useQuery({
+    queryKey: ['sessions', previewMeeting?.meeting_key, 'auto'],
+    queryFn: () => fetchSessions(previewMeeting!.meeting_key, 'auto'),
+    enabled: previewMeeting != null,
+  })
+
+  const sessions = useMemo(
+    () => sortSessionsByStart(sessionsQuery.data ?? []),
+    [sessionsQuery.data],
+  )
+
+  const countdownSession = useMemo(() => countdownTargetSession(sessions, nowDate), [sessions, nowDate])
+  const sprintWeekend = useMemo(() => isSprintWeekend(sessions), [sessions])
+
+  const priorYear = previewMeeting ? previewMeeting.year - 1 : null
+
+  const priorMeetingsQuery = useQuery({
+    queryKey: ['meetings', priorYear, 'auto'],
+    queryFn: () => fetchMeetings(priorYear!, 'auto'),
+    enabled: priorYear != null && previewMeeting != null,
+  })
+
+  const priorMeeting = useMemo(
+    () => findPriorYearMeetingByCircuit(priorMeetingsQuery.data ?? [], previewMeeting?.circuit_key),
+    [priorMeetingsQuery.data, previewMeeting?.circuit_key],
+  )
+
+  const priorSessionsQuery = useQuery({
+    queryKey: ['sessions', priorMeeting?.meeting_key, 'auto'],
+    queryFn: () => fetchSessions(priorMeeting!.meeting_key, 'auto'),
+    enabled: priorMeeting != null,
+  })
+
+  const priorRaceSession = useMemo(
+    () => findRaceSession(priorSessionsQuery.data ?? []),
+    [priorSessionsQuery.data],
+  )
+
+  const priorResultsQuery = useQuery({
+    queryKey: ['results', priorRaceSession?.session_key, 'auto'],
+    queryFn: () => fetchResults(priorRaceSession!.session_key, 'auto'),
+    enabled: priorRaceSession != null,
+  })
+
+  const priorGridQuery = useQuery({
+    queryKey: ['grid', priorRaceSession?.session_key, 'auto'],
+    queryFn: () => fetchStartingGrid(priorRaceSession!.session_key, 'auto'),
+    enabled: priorRaceSession != null,
+  })
+
+  const trackOutlineQuery = useQuery({
+    queryKey: ['track-outline', previewMeeting?.circuit_key, previewMeeting?.year],
+    queryFn: () => fetchTrackOutline(previewMeeting!.circuit_key!, previewMeeting!.year),
+    enabled: previewMeeting?.circuit_key != null && previewMeeting.circuit_key > 0,
+  })
+
+  const championshipQuery = useQuery({
+    queryKey: ['championship-hub', latestSeason],
+    queryFn: () => fetchChampionshipHub(latestSeason!),
+    enabled: latestSeason != null,
+  })
+
+  const podium = useMemo(() => extractPodium(priorResultsQuery.data ?? []), [priorResultsQuery.data])
+  const pole = useMemo(() => extractPole(priorGridQuery.data ?? []), [priorGridQuery.data])
+  const titleFight = useMemo(
+    () => (championshipQuery.data ? buildTitleFightContext(championshipQuery.data) : []),
+    [championshipQuery.data],
+  )
+
+  const accent = countryAccent(previewMeeting)
+  const isFirstTimeCircuit = priorMeeting == null && priorYear != null && !priorMeetingsQuery.isLoading
+
+  if (seasonsQuery.isLoading || meetingsQuery.isLoading) {
+    return <div className="page loading-state" data-testid="preview-loading">loading preview…</div>
+  }
+
+  if (seasonsQuery.isError || meetingsQuery.isError) {
+    const err = seasonsQuery.error ?? meetingsQuery.error
+    return (
+      <div className="page error-box" data-testid="preview-error">
+        {err instanceof Error ? err.message : 'Failed to load preview'}
+      </div>
+    )
+  }
+
+  if (!previewMeeting) {
+    return (
+      <div className="preview-page" data-testid="preview-season-over">
+        <div className="preview-empty">
+          <span className="preview-empty-eyebrow mono">box-box · race preview</span>
+          <h1 className="preview-empty-title">Season complete</h1>
+          <p className="preview-empty-sub">
+            No upcoming races on the {latestSeason ?? 'current'} calendar. Check back when the next season schedule is
+            published.
+          </p>
+        </div>
+        {titleFight.length > 0 && (
+          <TitleFightCard
+            loading={championshipQuery.isLoading}
+            error={championshipQuery.isError ? (championshipQuery.error as Error) : null}
+            drivers={titleFight}
+            sprintWeekend={false}
+            season={latestSeason}
+          />
+        )}
+      </div>
+    )
+  }
+
+  return (
+    <div className="preview-page" data-testid="preview-page">
+      <PreviewHeader
+        meeting={previewMeeting}
+        sessions={sessions}
+        countdownSession={countdownSession}
+        now={nowDate}
+        accent={accent}
+      />
+
+      <div className="preview-grid">
+        <TrackOutlineCard
+          outline={trackOutlineQuery.data}
+          loading={trackOutlineQuery.isLoading}
+          error={trackOutlineQuery.isError ? (trackOutlineQuery.error as Error) : null}
+          accent={accent}
+        />
+
+        <LastYearCard
+          year={priorMeeting?.year ?? priorYear}
+          loading={priorMeetingsQuery.isLoading || priorSessionsQuery.isLoading || priorResultsQuery.isLoading}
+          error={
+            priorMeetingsQuery.isError
+              ? (priorMeetingsQuery.error as Error)
+              : priorResultsQuery.isError
+                ? (priorResultsQuery.error as Error)
+                : null
+          }
+          podium={podium}
+          pole={pole}
+          isFirstTime={isFirstTimeCircuit}
+        />
+      </div>
+
+      <TitleFightCard
+        loading={championshipQuery.isLoading}
+        error={championshipQuery.isError ? (championshipQuery.error as Error) : null}
+        drivers={titleFight}
+        sprintWeekend={sprintWeekend}
+        season={latestSeason}
+      />
+    </div>
+  )
+}

frontend/src/router.tsx

@@ -6,11 +6,17 @@ import { DataLibraryPage } from './pages/DataLibraryPage'
 import { LiveTimingPage } from './pages/LiveTimingPage'
 import { BriefingPage } from './pages/BriefingPage'
 import { ChampionshipPage } from './pages/ChampionshipPage'
+import { DriverProfilePage } from './pages/DriverProfilePage'
+import { RacePreviewPage } from './pages/RacePreviewPage'
 
 type RaceHubSearch = {
   session_key?: number
 }
 
+type DriverProfileSearch = {
+  year?: number
+}
+
 const rootRoute = createRootRoute({
   component: () => (
     <>
@@ -64,12 +70,32 @@ export const championshipRoute = createRoute({
   component: ChampionshipPage,
 })
 
+export const driverProfileRoute = createRoute({
+  getParentRoute: () => rootRoute,
+  path: '/drivers/$driverNumber',
+  validateSearch: (search: Record<string, unknown>): DriverProfileSearch => {
+    const year = Number(search.year)
+    return Number.isFinite(year) && year > 0 ? { year } : {}
+  },
+  component: function DriverProfileRoute() {
+    const { driverNumber } = driverProfileRoute.useParams()
+    const { year } = driverProfileRoute.useSearch()
+    return <DriverProfilePage driverNumber={Number(driverNumber) || 0} year={year} />
+  },
+})
+
 export const briefingRoute = createRoute({
   getParentRoute: () => rootRoute,
   path: '/briefing',
   component: BriefingPage,
 })
 
+export const previewRoute = createRoute({
+  getParentRoute: () => rootRoute,
+  path: '/preview',
+  component: RacePreviewPage,
+})
+
 const routeTree = rootRoute.addChildren([
   commandCenterRoute,
   raceHubRoute,
@@ -77,7 +103,9 @@ const routeTree = rootRoute.addChildren([
   dataLibraryRoute,
   liveTimingRoute,
   championshipRoute,
+  driverProfileRoute,
   briefingRoute,
+  previewRoute,
 ])
 
 export const router = createRouter({ routeTree })

frontend/src/styles/chapters.css

@@ -0,0 +1,154 @@
+.chapter-strip {
+  display: flex;
+  flex-direction: column;
+  gap: var(--s3);
+}
+
+.chapter-strip-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: var(--s4);
+}
+
+.chapter-strip-title {
+  font-size: 11px;
+  font-weight: 600;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: var(--text-3);
+}
+
+.chapter-strip-actions {
+  display: flex;
+  align-items: center;
+  gap: var(--s2);
+}
+
+.chapter-tour-btn {
+  font-family: var(--f-mono);
+  font-size: 11px;
+  padding: var(--s1) var(--s3);
+  border: 1px solid var(--border);
+  border-radius: var(--s1);
+  background: var(--surface);
+  color: var(--text-2);
+  cursor: pointer;
+  transition: background 0.15s, border-color 0.15s, color 0.15s;
+}
+
+.chapter-tour-btn:hover,
+.chapter-tour-btn.active {
+  background: var(--surface-h);
+  border-color: var(--border-2);
+  color: var(--text);
+}
+
+.chapter-strip-scroll {
+  display: flex;
+  gap: var(--s3);
+  overflow-x: auto;
+  padding-bottom: var(--s2);
+  scroll-snap-type: x mandatory;
+  -webkit-overflow-scrolling: touch;
+}
+
+.chapter-card {
+  flex: 0 0 min(240px, 72vw);
+  display: flex;
+  flex-direction: column;
+  gap: var(--s2);
+  padding: var(--s3) var(--s4);
+  border: 1px solid var(--border);
+  border-radius: var(--s2);
+  background: var(--surface);
+  text-align: left;
+  cursor: pointer;
+  scroll-snap-align: start;
+  transition: border-color 0.15s, background 0.15s, box-shadow 0.15s;
+}
+
+.chapter-card:hover {
+  background: var(--surface-h);
+  border-color: var(--border-2);
+}
+
+.chapter-card.active {
+  border-color: var(--accent, var(--red));
+  background: var(--surface-h);
+  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent, var(--red)) 35%, transparent);
+}
+
+.chapter-card.tour-active {
+  border-color: var(--yellow);
+  box-shadow: 0 0 0 1px color-mix(in srgb, var(--yellow) 40%, transparent);
+}
+
+.chapter-card-top {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: var(--s3);
+}
+
+.chapter-kind {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  min-width: 28px;
+  height: 20px;
+  padding: 0 var(--s2);
+  border-radius: var(--s1);
+  font-family: var(--f-mono);
+  font-size: 10px;
+  font-weight: 700;
+  letter-spacing: 0.04em;
+  background: var(--bg);
+  color: var(--text-2);
+  border: 1px solid var(--border);
+}
+
+.chapter-card.active .chapter-kind {
+  color: var(--text);
+  border-color: var(--border-2);
+}
+
+.chapter-kind--safety_car,
+.chapter-kind--virtual_safety_car {
+  color: var(--orange, #f90);
+}
+
+.chapter-kind--red_flag {
+  color: var(--red);
+}
+
+.chapter-kind--decisive_swing {
+  color: var(--green, #22c55e);
+}
+
+.chapter-kind--finish {
+  color: var(--yellow);
+}
+
+.chapter-lap-range {
+  font-family: var(--f-mono);
+  font-size: 10px;
+  color: var(--text-3);
+  white-space: nowrap;
+}
+
+.chapter-headline {
+  font-size: 13px;
+  line-height: 1.35;
+  color: var(--text);
+  display: -webkit-box;
+  -webkit-line-clamp: 2;
+  -webkit-box-orient: vertical;
+  overflow: hidden;
+}
+
+.chapter-strip-empty {
+  font-size: 12px;
+  color: var(--text-3);
+  padding: var(--s3) 0;
+}

frontend/src/styles/digest.css

@@ -0,0 +1,178 @@
+/* ── Calendar-aware paddock digest ── */
+
+.digest-sticky {
+  position: sticky;
+  top: 0;
+  z-index: 20;
+  margin-bottom: var(--s5);
+  padding: var(--s4) var(--s5);
+  background: color-mix(in srgb, var(--bg) 92%, transparent);
+  backdrop-filter: blur(8px);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+}
+
+.digest-sticky-head {
+  display: flex;
+  align-items: baseline;
+  gap: var(--s3);
+  flex-wrap: wrap;
+  margin-bottom: var(--s3);
+}
+
+.digest-sticky-title {
+  font-size: 15px;
+  font-weight: 600;
+  color: var(--text);
+  margin: 0;
+}
+
+.digest-sticky-count {
+  font-size: 11px;
+  color: var(--text-3);
+  font-family: var(--f-mono);
+  letter-spacing: 0.04em;
+}
+
+.digest-sticky-tags {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--s2);
+  align-items: center;
+}
+
+.digest-tag-chip {
+  display: inline-flex;
+  align-items: center;
+  gap: var(--s2);
+  padding: 2px 8px;
+  border-radius: 999px;
+  border: 1px solid var(--border-2);
+  background: var(--surface);
+  color: var(--text-2);
+  font-size: 11px;
+  font-family: var(--f-mono);
+  cursor: pointer;
+  transition: border-color 0.1s, color 0.1s, background 0.1s;
+}
+
+.digest-tag-chip:hover {
+  color: var(--text);
+  background: var(--surface-h);
+}
+
+.digest-tag-chip.active {
+  color: var(--text);
+  border-color: var(--tag-colour, var(--red));
+  box-shadow: 0 0 0 1px color-mix(in srgb, var(--tag-colour, var(--red)) 35%, transparent);
+}
+
+.digest-tag-dot {
+  width: 7px;
+  height: 7px;
+  border-radius: 50%;
+  background: var(--tag-colour, var(--text-3));
+  flex-shrink: 0;
+}
+
+.digest-filter-clear {
+  padding: 2px 8px;
+  border: 1px dashed var(--border-2);
+  border-radius: 999px;
+  background: none;
+  color: var(--text-3);
+  font-size: 11px;
+  font-family: var(--f-mono);
+  cursor: pointer;
+}
+
+.digest-filter-clear:hover {
+  color: var(--text);
+  border-color: var(--border-2);
+}
+
+.digest-section {
+  margin-bottom: var(--s6);
+}
+
+.digest-section-head {
+  display: flex;
+  align-items: baseline;
+  gap: var(--s3);
+  margin-bottom: var(--s4);
+  padding-bottom: var(--s3);
+  border-bottom: 1px solid var(--border);
+}
+
+.digest-section-title {
+  font-size: 13px;
+  font-weight: 600;
+  color: var(--text);
+  margin: 0;
+  letter-spacing: 0.02em;
+}
+
+.digest-section-count {
+  font-size: 11px;
+  color: var(--text-3);
+  font-family: var(--f-mono);
+}
+
+.digest-recent-section .digest-section-title {
+  color: var(--text-2);
+}
+
+.bp-card-tags {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--s2);
+  margin-top: var(--s2);
+}
+
+.bp-card-tag {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  padding: 1px 6px;
+  border-radius: 999px;
+  border: 1px solid var(--border);
+  background: var(--bg);
+  color: var(--text-2);
+  font-size: 10px;
+  font-family: var(--f-mono);
+  cursor: pointer;
+}
+
+.bp-card-tag:hover {
+  color: var(--text);
+  border-color: var(--border-2);
+}
+
+.bp-card-tag.active {
+  border-color: var(--tag-colour, var(--red));
+}
+
+.cc-brief-digest-meta {
+  display: flex;
+  align-items: center;
+  gap: var(--s2);
+  margin-bottom: var(--s3);
+  font-size: 11px;
+  color: var(--text-3);
+  font-family: var(--f-mono);
+}
+
+.cc-brief-digest-tags {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--s2);
+}
+
+.cc-brief-tag {
+  font-size: 10px;
+  padding: 1px 6px;
+  border-radius: 999px;
+  border: 1px solid var(--border);
+  color: var(--text-2);
+  font-family: var(--f-mono);
+}

frontend/src/styles/driver-profile.css

@@ -0,0 +1,289 @@
+/* Driver profile page (/drivers/$driverNumber) */
+
+.dp-page {
+  max-width: 1100px;
+  margin: 0 auto;
+  padding: var(--s6) var(--s5);
+  display: flex;
+  flex-direction: column;
+  gap: var(--s6);
+}
+
+/* --- header --- */
+
+.dp-header {
+  position: relative;
+  display: flex;
+  flex-wrap: wrap;
+  align-items: flex-end;
+  justify-content: space-between;
+  gap: var(--s5);
+  padding: var(--s5);
+  padding-left: var(--s6);
+  border: 1px solid var(--border);
+  border-left: 4px solid var(--red);
+  border-radius: var(--r2);
+  background: var(--surface);
+}
+
+.dp-title-row {
+  display: flex;
+  align-items: baseline;
+  gap: var(--s3);
+}
+
+.dp-code {
+  font-size: 13px;
+  letter-spacing: 0.12em;
+  color: var(--text-2);
+  text-transform: uppercase;
+}
+
+.dp-num {
+  font-size: 13px;
+  font-weight: 700;
+}
+
+.dp-name {
+  margin: var(--s2) 0;
+  font-size: 30px;
+  line-height: 1.1;
+  letter-spacing: -0.01em;
+}
+
+.dp-team {
+  display: flex;
+  align-items: center;
+  gap: var(--s3);
+  font-size: 13px;
+  color: var(--text-2);
+}
+
+.dp-team-swatch {
+  width: 10px;
+  height: 10px;
+  border-radius: 2px;
+}
+
+.dp-season {
+  color: var(--text-3);
+}
+
+.dp-stat-rail {
+  display: flex;
+  gap: var(--s5);
+}
+
+.dp-stat {
+  min-width: 72px;
+}
+
+.dp-stat-value {
+  font-size: 22px;
+  font-weight: 700;
+}
+
+.dp-stat-label {
+  font-size: 11px;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  color: var(--text-3);
+}
+
+.dp-back {
+  position: absolute;
+  top: var(--s4);
+  right: var(--s5);
+  font-size: 12px;
+  color: var(--text-3);
+  text-decoration: none;
+}
+
+.dp-back:hover {
+  color: var(--text);
+}
+
+/* --- sections --- */
+
+.dp-section {
+  display: flex;
+  flex-direction: column;
+  gap: var(--s4);
+}
+
+.dp-section-title {
+  font-size: 12px;
+  text-transform: uppercase;
+  letter-spacing: 0.1em;
+  color: var(--text-2);
+}
+
+.dp-empty {
+  padding: var(--s5);
+  border: 1px dashed var(--border);
+  border-radius: var(--r2);
+  color: var(--text-3);
+  font-size: 13px;
+}
+
+/* --- charts --- */
+
+.dp-form-grid {
+  display: grid;
+  grid-template-columns: minmax(0, 2fr) minmax(200px, 1fr);
+  gap: var(--s5);
+  align-items: stretch;
+}
+
+@media (max-width: 760px) {
+  .dp-form-grid {
+    grid-template-columns: 1fr;
+  }
+}
+
+.dp-chart {
+  margin: 0;
+  padding: var(--s4);
+  border: 1px solid var(--border);
+  border-radius: var(--r2);
+  background: var(--surface);
+  min-width: 0;
+}
+
+.dp-chart-caption {
+  font-size: 11px;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  color: var(--text-3);
+  margin-bottom: var(--s3);
+}
+
+.dp-chart-svg {
+  display: block;
+  width: 100%;
+  height: auto;
+}
+
+.dp-chart-scroll {
+  overflow-x: auto;
+}
+
+.dp-gridline {
+  stroke: var(--border);
+  stroke-width: 1;
+}
+
+.dp-zeroline {
+  stroke: var(--text-3);
+  stroke-width: 1;
+  stroke-dasharray: 3 3;
+}
+
+.dp-axis {
+  fill: var(--text-3);
+  font-family: var(--f-mono);
+  font-size: 10px;
+}
+
+.dp-delta-svg {
+  display: block;
+}
+
+.dp-delta-val {
+  fill: var(--text-2);
+  font-size: 10px;
+}
+
+/* --- form strip --- */
+
+.dp-form-strip {
+  padding: var(--s4);
+  border: 1px solid var(--border);
+  border-radius: var(--r2);
+  background: var(--surface);
+  display: flex;
+  flex-direction: column;
+}
+
+.dp-form-bars {
+  flex: 1;
+  display: flex;
+  align-items: flex-end;
+  gap: var(--s3);
+  min-height: 110px;
+}
+
+.dp-form-bar {
+  flex: 1;
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+  justify-content: flex-end;
+  align-items: center;
+  gap: var(--s2);
+}
+
+.dp-form-bar-fill {
+  width: 100%;
+  max-width: 34px;
+  border-radius: 2px 2px 0 0;
+  opacity: 0.9;
+}
+
+.dp-form-bar-val {
+  font-size: 11px;
+  color: var(--text-2);
+}
+
+/* --- rounds table --- */
+
+.dp-scroll {
+  overflow-x: auto;
+  border: 1px solid var(--border);
+  border-radius: var(--r2);
+  background: var(--surface);
+}
+
+.dp-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 13px;
+}
+
+.dp-table th {
+  padding: var(--s3) var(--s4);
+  font-family: var(--f-mono);
+  font-size: 11px;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  color: var(--text-3);
+  border-bottom: 1px solid var(--border);
+}
+
+.dp-table td {
+  padding: var(--s3) var(--s4);
+  border-bottom: 1px solid var(--border);
+  white-space: nowrap;
+}
+
+.dp-table tbody tr:last-child td {
+  border-bottom: none;
+}
+
+.dp-table th.l,
+.dp-table td.l {
+  text-align: left;
+}
+
+.dp-table th.r,
+.dp-table td.r {
+  text-align: right;
+}
+
+.dp-td-dim {
+  color: var(--text-3);
+}
+
+.dp-flag {
+  margin-right: var(--s3);
+}

frontend/src/styles/h2h.css

@@ -0,0 +1,130 @@
+/* Teammate head-to-head bars (issue #23). */
+
+.h2h-section {
+  margin: 20px 0 24px;
+  padding: 16px 18px;
+  background: var(--surface-1, rgba(255, 255, 255, 0.03));
+  border: 1px solid var(--border);
+  border-radius: 8px;
+}
+
+.h2h-section-head {
+  display: flex;
+  align-items: baseline;
+  gap: 10px;
+  margin-bottom: 14px;
+}
+
+.h2h-section-title {
+  font-size: 13px;
+  font-weight: 600;
+  letter-spacing: 0.04em;
+  text-transform: uppercase;
+  color: var(--text-2);
+}
+
+.h2h-section-sub {
+  font-size: 11px;
+  font-family: var(--f-mono);
+  color: var(--text-3);
+}
+
+.h2h-list {
+  display: flex;
+  flex-direction: column;
+  gap: 10px;
+}
+
+.h2h-row {
+  display: grid;
+  grid-template-columns: minmax(100px, 140px) 1fr;
+  align-items: center;
+  gap: 12px;
+}
+
+.h2h-team {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  min-width: 0;
+}
+
+.h2h-team-name {
+  font-size: 12px;
+  color: var(--text-2);
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.h2h-extra {
+  font-size: 10px;
+  color: var(--text-3);
+  flex-shrink: 0;
+}
+
+.h2h-bar-wrap {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+}
+
+.h2h-tla {
+  font-size: 11px;
+  font-weight: 700;
+  color: var(--text);
+  flex-shrink: 0;
+  width: 28px;
+}
+
+.h2h-tla--left {
+  text-align: right;
+}
+
+.h2h-tla--right {
+  text-align: left;
+}
+
+.h2h-bar {
+  position: relative;
+  flex: 1;
+  display: flex;
+  height: 22px;
+  border-radius: 4px;
+  overflow: hidden;
+  background: rgba(255, 255, 255, 0.04);
+}
+
+.h2h-bar-seg {
+  height: 100%;
+  transition: width 0.2s ease;
+}
+
+.h2h-bar-seg--muted {
+  opacity: 0.35;
+}
+
+.h2h-score {
+  position: absolute;
+  inset: 0;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  font-size: 11px;
+  font-weight: 700;
+  color: #fff;
+  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.6);
+  pointer-events: none;
+}
+
+@media (max-width: 640px) {
+  .h2h-row {
+    grid-template-columns: 1fr;
+    gap: 4px;
+  }
+
+  .h2h-bar-wrap {
+    width: 100%;
+  }
+}

frontend/src/styles/preview.css

@@ -0,0 +1,309 @@
+.preview-page {
+  display: flex;
+  flex-direction: column;
+  gap: var(--s6);
+  padding: var(--s6);
+  max-width: 1200px;
+  margin: 0 auto;
+}
+
+.preview-empty {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: var(--s4);
+  min-height: 320px;
+  text-align: center;
+  padding: var(--s8);
+  background: var(--surface);
+  border: 1px solid rgba(255, 255, 255, 0.08);
+  border-radius: 8px;
+}
+
+.preview-empty-eyebrow {
+  font-size: 0.7rem;
+  letter-spacing: 0.12em;
+  text-transform: uppercase;
+  color: var(--text-3);
+}
+
+.preview-empty-title {
+  font-size: 1.5rem;
+  font-weight: 600;
+  margin: 0;
+}
+
+.preview-empty-sub {
+  color: var(--text-2);
+  max-width: 36rem;
+  margin: 0;
+}
+
+.preview-header {
+  display: flex;
+  background: var(--surface);
+  border: 1px solid rgba(255, 255, 255, 0.08);
+  border-radius: 8px;
+  overflow: hidden;
+  min-height: 140px;
+}
+
+.preview-header-accent {
+  width: 4px;
+  flex-shrink: 0;
+  background: var(--preview-accent, var(--gp-accent));
+  box-shadow: 0 0 12px var(--preview-accent, var(--gp-accent));
+}
+
+.preview-header-body {
+  flex: 1;
+  padding: var(--s5);
+  display: flex;
+  flex-direction: column;
+  gap: var(--s4);
+  min-width: 0;
+}
+
+.preview-header-top {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: flex-start;
+  justify-content: space-between;
+  gap: var(--s4);
+}
+
+.preview-gp-name {
+  font-size: 1.4rem;
+  font-weight: 600;
+  margin: 0;
+  display: flex;
+  align-items: center;
+  gap: var(--s3);
+}
+
+.preview-gp-flag {
+  font-size: 1.5rem;
+  line-height: 1;
+}
+
+.preview-circuit {
+  color: var(--text-2);
+  font-size: 0.9rem;
+  margin: 0;
+}
+
+.preview-countdown {
+  text-align: right;
+}
+
+.preview-countdown-label {
+  display: block;
+  font-size: 0.7rem;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--text-3);
+  margin-bottom: var(--s1);
+}
+
+.preview-countdown-value {
+  font-family: var(--mono);
+  font-size: 1.1rem;
+  font-variant-numeric: tabular-nums;
+  color: var(--text-1);
+}
+
+.preview-schedule {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
+  gap: var(--s2);
+}
+
+.preview-schedule-item {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  padding: var(--s2) var(--s3);
+  background: rgba(255, 255, 255, 0.03);
+  border-radius: 4px;
+  font-size: 0.8rem;
+}
+
+.preview-schedule-name {
+  font-weight: 600;
+  color: var(--text-1);
+}
+
+.preview-schedule-time {
+  font-family: var(--mono);
+  font-size: 0.75rem;
+  color: var(--text-2);
+}
+
+.preview-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
+  gap: var(--s5);
+}
+
+.preview-card {
+  background: var(--surface);
+  border: 1px solid rgba(255, 255, 255, 0.08);
+  border-radius: 8px;
+  padding: var(--s5);
+  display: flex;
+  flex-direction: column;
+  gap: var(--s4);
+  min-height: 200px;
+}
+
+.preview-card-title {
+  font-size: 0.75rem;
+  letter-spacing: 0.1em;
+  text-transform: uppercase;
+  color: var(--text-3);
+  margin: 0;
+}
+
+.preview-card-sub {
+  font-size: 0.85rem;
+  color: var(--text-2);
+  margin: calc(-1 * var(--s2)) 0 0;
+}
+
+.preview-track-stage {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex: 1;
+  min-height: 180px;
+  padding: var(--s4);
+}
+
+.preview-track-svg {
+  width: 100%;
+  max-width: 280px;
+  height: auto;
+}
+
+.preview-track-outline {
+  fill: none;
+  stroke: var(--preview-accent, var(--gp-accent));
+  stroke-width: 1.8;
+  stroke-linecap: round;
+  stroke-linejoin: round;
+  opacity: 0.9;
+}
+
+.preview-track-shadow {
+  fill: none;
+  stroke: rgba(0, 0, 0, 0.5);
+  stroke-width: 3;
+  stroke-linecap: round;
+  stroke-linejoin: round;
+}
+
+.preview-podium {
+  display: flex;
+  flex-direction: column;
+  gap: var(--s3);
+}
+
+.preview-podium-row {
+  display: flex;
+  align-items: center;
+  gap: var(--s3);
+  font-size: 0.9rem;
+}
+
+.preview-podium-pos {
+  width: 1.5rem;
+  font-family: var(--mono);
+  font-weight: 600;
+  color: var(--text-3);
+}
+
+.preview-podium-code {
+  font-weight: 600;
+  min-width: 2.5rem;
+}
+
+.preview-podium-team {
+  color: var(--text-2);
+  font-size: 0.8rem;
+}
+
+.preview-pole {
+  padding-top: var(--s3);
+  border-top: 1px solid rgba(255, 255, 255, 0.06);
+  font-size: 0.85rem;
+  color: var(--text-2);
+}
+
+.preview-pole strong {
+  color: var(--text-1);
+}
+
+.preview-title-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 0.85rem;
+}
+
+.preview-title-table th,
+.preview-title-table td {
+  padding: var(--s2) var(--s3);
+  text-align: left;
+  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
+}
+
+.preview-title-table th {
+  font-size: 0.7rem;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: var(--text-3);
+  font-weight: 500;
+}
+
+.preview-title-table td.mono {
+  font-family: var(--mono);
+  font-variant-numeric: tabular-nums;
+}
+
+.preview-sprint-note {
+  font-size: 0.8rem;
+  color: var(--text-2);
+  margin: 0;
+  padding: var(--s3);
+  background: rgba(255, 255, 255, 0.03);
+  border-radius: 4px;
+}
+
+.preview-section-state {
+  flex: 1;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  color: var(--text-3);
+  font-size: 0.85rem;
+  text-align: center;
+  padding: var(--s5);
+}
+
+.preview-section-state.error {
+  color: var(--red, #e74c3c);
+}
+
+@media (max-width: 640px) {
+  .preview-page {
+    padding: var(--s4);
+  }
+
+  .preview-header-top {
+    flex-direction: column;
+  }
+
+  .preview-countdown {
+    text-align: left;
+  }
+}

frontend/src/styles/replay-map.css

@@ -0,0 +1,161 @@
+.rs-replay-shell {
+  display: grid;
+  grid-template-columns: minmax(0, 1.4fr) minmax(260px, 0.8fr);
+  gap: var(--s5);
+  align-items: stretch;
+}
+
+.rs-replay-main {
+  min-width: 0;
+}
+
+.rs-replay-tools {
+  display: flex;
+  align-items: center;
+  flex-wrap: wrap;
+  gap: var(--s3);
+  margin-top: var(--s3);
+}
+
+.rs-tool-btn,
+.rs-speed-btn {
+  height: 28px;
+  padding: 0 var(--s4);
+  font-family: var(--f-mono);
+  font-size: 10px;
+  font-weight: 700;
+  color: var(--text-2);
+  background: var(--surface);
+  border: 1px solid var(--border-2);
+  border-radius: 2px;
+  cursor: pointer;
+}
+
+.rs-tool-btn:hover,
+.rs-speed-btn:hover {
+  color: var(--text);
+  border-color: var(--text-3);
+}
+
+.rs-tool-btn.active,
+.rs-speed-btn.active {
+  color: var(--text);
+  border-color: var(--red);
+  background: rgba(230, 36, 41, 0.12);
+}
+
+.rs-speed-group {
+  display: inline-flex;
+  gap: 2px;
+}
+
+.rs-replay-map-slot {
+  min-width: 0;
+}
+
+.rs-replay-map-placeholder {
+  min-height: 244px;
+  display: grid;
+  place-items: center;
+  padding: var(--s5);
+  color: var(--text-3);
+  font-family: var(--f-mono);
+  font-size: 11px;
+  text-align: center;
+  border: 1px dashed var(--border-2);
+  background: var(--surface);
+}
+
+.replay-map-panel {
+  min-height: 244px;
+  height: 100%;
+  border: 1px solid var(--border);
+  background: var(--surface);
+}
+
+.replay-map-stage {
+  position: relative;
+  min-height: 244px;
+  height: 100%;
+}
+
+.replay-map-svg {
+  width: 100%;
+  height: 100%;
+  min-height: 244px;
+  display: block;
+  background: radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.04), transparent 62%);
+}
+
+.replay-map-outline-shadow,
+.replay-map-outline {
+  fill: none;
+  vector-effect: non-scaling-stroke;
+  stroke-linecap: round;
+  stroke-linejoin: round;
+}
+
+.replay-map-outline-shadow {
+  stroke: rgba(255, 255, 255, 0.08);
+  stroke-width: 5;
+}
+
+.replay-map-outline {
+  stroke: var(--text-2);
+  stroke-width: 1.8;
+}
+
+.replay-car {
+  cursor: pointer;
+  outline: none;
+}
+
+.replay-car circle {
+  stroke: var(--bg);
+  stroke-width: 0.8;
+  filter: drop-shadow(0 1px 3px rgba(0, 0, 0, 0.55));
+}
+
+.replay-car text {
+  fill: #fff;
+  font-family: var(--f-mono);
+  font-size: 2.6px;
+  font-weight: 800;
+  text-anchor: middle;
+  pointer-events: none;
+  paint-order: stroke;
+  stroke: rgba(0, 0, 0, 0.75);
+  stroke-width: 0.7;
+}
+
+.replay-car:not(.replay-car-pinned) text {
+  opacity: 0;
+}
+
+.replay-car:hover text,
+.replay-car:focus-visible text,
+.replay-car-pinned text {
+  opacity: 1;
+}
+
+.replay-car-pinned circle {
+  stroke: #fff;
+  stroke-width: 1.2;
+}
+
+.replay-map-empty {
+  min-height: 244px;
+  display: grid;
+  place-items: center;
+  padding: var(--s5);
+  color: var(--text-3);
+  font-family: var(--f-mono);
+  font-size: 11px;
+  text-align: center;
+}
+
+@media (max-width: 860px) {
+  .rs-replay-shell {
+    grid-template-columns: 1fr;
+  }
+}

frontend/src/styles/rivalry.css

@@ -0,0 +1,134 @@
+.rivalry {
+  display: flex;
+  flex-direction: column;
+  gap: var(--s5);
+}
+
+.rivalry-pickers {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--s4);
+  align-items: flex-end;
+}
+
+.rivalry-vs {
+  font-size: 11px;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: var(--text-3);
+  padding-bottom: var(--s3);
+}
+
+.rivalry-picker {
+  display: flex;
+  flex-direction: column;
+  gap: var(--s2);
+  min-width: 200px;
+}
+
+.rivalry-picker-label {
+  font-family: var(--f-mono);
+  font-size: 11px;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: var(--text-3);
+}
+
+.rivalry-picker-select {
+  font-family: var(--f-mono);
+  font-size: 13px;
+  padding: var(--s2) var(--s3);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  background: var(--surface-2);
+  color: var(--text);
+}
+
+.rivalry-picker-select:focus {
+  outline: 2px solid var(--red);
+  outline-offset: 1px;
+}
+
+.rivalry-h2h {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: var(--s4) var(--s5);
+  padding: var(--s4) var(--s5);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  background: var(--surface-2);
+}
+
+.rivalry-h2h-score {
+  display: flex;
+  align-items: baseline;
+  gap: var(--s3);
+}
+
+.rivalry-h2h-code {
+  font-size: 14px;
+  font-weight: 700;
+}
+
+.rivalry-h2h-num {
+  font-size: 24px;
+  font-weight: 700;
+  color: var(--text);
+}
+
+.rivalry-h2h-meta {
+  font-family: var(--f-mono);
+  font-size: 11px;
+  color: var(--text-3);
+}
+
+.rivalry-strip {
+  display: flex;
+  align-items: center;
+  gap: var(--s2);
+  margin-left: auto;
+}
+
+.rivalry-strip-label {
+  font-family: var(--f-mono);
+  font-size: 10px;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: var(--text-3);
+  margin-right: var(--s2);
+}
+
+.rivalry-chip {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 1px;
+  padding: var(--s1) var(--s3);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  background: var(--surface);
+}
+
+.rivalry-chip-round {
+  font-size: 9px;
+  color: var(--text-3);
+}
+
+.rivalry-chip-winner {
+  font-size: 11px;
+  font-weight: 700;
+}
+
+.rivalry-section {
+  display: flex;
+  flex-direction: column;
+  gap: var(--s3);
+}
+
+.rivalry-caption {
+  font-family: var(--f-mono);
+  font-size: 11px;
+  color: var(--text-3);
+  margin: 0;
+}

frontend/src/test/BriefingPage.test.tsx

@@ -0,0 +1,211 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { render, screen, waitFor, fireEvent, within } from '@testing-library/react'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { BriefingPage } from '../pages/BriefingPage'
+import type { ChampHubDriver, ChampHubTeam, ChampionshipHub, Meeting, NewsItem } from '../types'
+
+vi.mock('../api', () => ({
+  fetchNews: vi.fn(),
+  fetchNewsArticle: vi.fn(),
+  markNewsRead: vi.fn(),
+  fetchSeasons: vi.fn(),
+  fetchSeasonMeetings: vi.fn(),
+  fetchChampionshipHub: vi.fn(),
+}))
+
+import {
+  fetchNews,
+  fetchNewsArticle,
+  fetchSeasons,
+  fetchSeasonMeetings,
+  fetchChampionshipHub,
+  markNewsRead,
+} from '../api'
+
+const mockFetchNews = vi.mocked(fetchNews)
+const mockFetchNewsArticle = vi.mocked(fetchNewsArticle)
+const mockFetchSeasons = vi.mocked(fetchSeasons)
+const mockFetchSeasonMeetings = vi.mocked(fetchSeasonMeetings)
+const mockFetchHub = vi.mocked(fetchChampionshipHub)
+const mockMarkNewsRead = vi.mocked(markNewsRead)
+
+const bahrain: Meeting = {
+  meeting_key: 1,
+  meeting_name: 'Bahrain',
+  meeting_official_name: 'Bahrain GP',
+  location: 'Sakhir',
+  country_name: 'Bahrain',
+  country_code: 'BRN',
+  country_flag: '',
+  circuit_short_name: 'Sakhir',
+  date_start: '2025-03-14T00:00:00+00:00',
+  date_end: '2025-03-16T23:59:59+00:00',
+  year: 2025,
+}
+
+const monaco: Meeting = {
+  meeting_key: 2,
+  meeting_name: 'Monaco',
+  meeting_official_name: 'Monaco GP',
+  location: 'Monaco',
+  country_name: 'Monaco',
+  country_code: 'MON',
+  country_flag: '',
+  circuit_short_name: 'Monaco',
+  date_start: '2025-05-23T00:00:00+00:00',
+  date_end: '2025-05-25T23:59:59+00:00',
+  year: 2025,
+}
+
+const drivers: ChampHubDriver[] = [
+  {
+    driver_number: 1,
+    name_acronym: 'VER',
+    full_name: 'Max Verstappen',
+    team_name: 'Red Bull',
+    team_colour: '3671c6',
+    points: 100,
+    position: 1,
+    wins: 3,
+    podiums: 5,
+    poles: 2,
+    form: [25, 18, 25],
+    cumulative: [25, 43, 68, 100],
+    teammate_wins: 4,
+    teammate_losses: 1,
+    round_positions: [],
+  },
+  {
+    driver_number: 4,
+    name_acronym: 'NOR',
+    full_name: 'Lando Norris',
+    team_name: 'McLaren',
+    team_colour: 'ff8000',
+    points: 80,
+    position: 2,
+    wins: 1,
+    podiums: 4,
+    poles: 1,
+    form: [18, 25, 18],
+    cumulative: [18, 36, 54, 80],
+    teammate_wins: 3,
+    teammate_losses: 2,
+    round_positions: [],
+  },
+]
+
+const teams: ChampHubTeam[] = [
+  { team_name: 'Red Bull', team_colour: '3671c6', points: 150, position: 1, wins: 4 },
+  { team_name: 'McLaren', team_colour: 'ff8000', points: 120, position: 2, wins: 2 },
+]
+
+const hub: ChampionshipHub = {
+  season: 2025,
+  round: 2,
+  total_rounds: 2,
+  rounds_left: 0,
+  last_race: 'Monaco GP',
+  round_labels: ['R1', 'R2'],
+  drivers,
+  teams,
+}
+
+const newsItems: NewsItem[] = [
+  {
+    source: 'autosport-f1',
+    title: 'Verstappen sets the pace in Bahrain',
+    url: 'https://example.com/bahrain-ver',
+    published_at: '2025-03-15T10:00:00Z',
+    fetched_at: '2025-03-15T11:00:00Z',
+    summary: 'Red Bull dominate opening practice',
+  },
+  {
+    source: 'racefans-f1',
+    title: 'Norris targets Monaco upgrade',
+    url: 'https://example.com/monaco-nor',
+    published_at: '2025-04-20T10:00:00Z',
+    fetched_at: '2025-04-20T11:00:00Z',
+    summary: 'McLaren bring new floor',
+  },
+  {
+    source: 'bbc-f1',
+    title: 'Undated paddock rumour',
+    url: 'https://example.com/undated',
+    fetched_at: '2025-04-21T11:00:00Z',
+  },
+]
+
+function renderPage() {
+  const queryClient = new QueryClient({
+    defaultOptions: { queries: { retry: false } },
+  })
+
+  return render(
+    <QueryClientProvider client={queryClient}>
+      <BriefingPage />
+    </QueryClientProvider>,
+  )
+}
+
+describe('BriefingPage digest layout', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    vi.setSystemTime(new Date('2025-04-10T12:00:00Z'))
+    mockFetchSeasons.mockResolvedValue([2025])
+    mockFetchSeasonMeetings.mockResolvedValue([bahrain, monaco])
+    mockFetchHub.mockResolvedValue(hub)
+    mockFetchNews.mockResolvedValue(newsItems)
+    mockFetchNewsArticle.mockResolvedValue({ title: 'Article', content: '<p>Body</p>' })
+    mockMarkNewsRead.mockResolvedValue(undefined)
+  })
+
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('renders sticky since-last header, GP sections, and recent bucket', async () => {
+    renderPage()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('digest-sticky-header')).toHaveTextContent('Since Bahrain')
+    })
+
+    expect(screen.getByTestId('digest-window-2')).toHaveTextContent('Monaco')
+    expect(screen.getByTestId('digest-window-1')).toHaveTextContent('Bahrain')
+    expect(screen.getByTestId('digest-recent')).toHaveTextContent('Undated paddock rumour')
+    expect(screen.getByText('Verstappen sets the pace in Bahrain')).toBeInTheDocument()
+    expect(screen.getByText('Norris targets Monaco upgrade')).toBeInTheDocument()
+  })
+
+  it('filters the digest when a tag chip is clicked', async () => {
+    renderPage()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('digest-sticky-header')).toBeInTheDocument()
+    })
+
+    const sticky = screen.getByTestId('digest-sticky-header')
+    const norTag = within(sticky).getByRole('button', { name: /^NOR$/i })
+    fireEvent.click(norTag)
+
+    await waitFor(() => {
+      expect(screen.queryByText('Verstappen sets the pace in Bahrain')).not.toBeInTheDocument()
+    })
+    expect(screen.getByText('Norris targets Monaco upgrade')).toBeInTheDocument()
+    expect(screen.getByTestId('digest-filter-clear')).toBeInTheDocument()
+
+    fireEvent.click(screen.getByTestId('digest-filter-clear'))
+    await waitFor(() => {
+      expect(screen.getByText('Verstappen sets the pace in Bahrain')).toBeInTheDocument()
+    })
+  })
+
+  it('preserves category tabs', async () => {
+    renderPage()
+
+    await waitFor(() => {
+      expect(screen.getByRole('tab', { name: /All/i })).toBeInTheDocument()
+    })
+    expect(screen.getByRole('tab', { name: /News/i })).toBeInTheDocument()
+  })
+})

frontend/src/test/ChampionshipPage.test.tsx

@@ -29,6 +29,7 @@ function driver(over: Partial<ChampHubDriver>): ChampHubDriver {
     poles: 4,
     form: [25, 18, 25, 15, 25],
     cumulative: [25, 43, 68, 83, 108, 200],
+    round_positions: [1, 2, 1, 3, 1, 1],
     teammate_wins: 9,
     teammate_losses: 1,
     ...over,
@@ -47,6 +48,7 @@ const drivers: ChampHubDriver[] = [
     position: 2,
     wins: 3,
     cumulative: [18, 36, 54, 80, 120, 160],
+    round_positions: [2, 1, 2, 2, 2, 2],
   }),
   driver({
     driver_number: 16,
@@ -58,6 +60,7 @@ const drivers: ChampHubDriver[] = [
     position: 3,
     wins: 1,
     cumulative: [15, 28, 40, 60, 90, 120],
+    round_positions: [3, 3, 3, 0, 3, 3],
   }),
 ]
 
@@ -129,6 +132,22 @@ describe('ChampionshipPage', () => {
     expect(screen.getByText('Cumulative points', { exact: false })).toBeInTheDocument()
   })
 
+  it('switches to the rivalry view with the top two drivers preselected', async () => {
+    renderPage()
+
+    await waitFor(() => expect(screen.getByTestId('championship')).toBeInTheDocument())
+
+    fireEvent.click(screen.getByTestId('champ-tab-rivalry'))
+    expect(screen.getByTestId('champ-view-rivalry')).toBeInTheDocument()
+    // Default pair is the top two in the standings: VER vs NOR.
+    expect(screen.getByTestId('rivalry-pick-a')).toHaveValue('1')
+    expect(screen.getByTestId('rivalry-pick-b')).toHaveValue('4')
+    // VER beats NOR in rounds 1, 3, 5, 6 → 4–2.
+    expect(screen.getByTestId('rivalry-h2h-num')).toHaveTextContent('4–2')
+    expect(screen.getByTestId('rivalry-points-race')).toBeInTheDocument()
+    expect(screen.getByTestId('rivalry-gap')).toBeInTheDocument()
+  })
+
   it('switches to the simulator view and projects standings', async () => {
     renderPage()
 
@@ -150,4 +169,61 @@ describe('ChampionshipPage', () => {
     })
     expect(screen.getByText('No championship data')).toBeInTheDocument()
   })
+
+  it('renders teammate battles section ordered by closest split', async () => {
+    const h2hDrivers: ChampHubDriver[] = [
+      driver({ driver_number: 1, name_acronym: 'VER', team_name: 'Red Bull', points: 200, position: 1 }),
+      driver({
+        driver_number: 4,
+        name_acronym: 'NOR',
+        full_name: 'Lando Norris',
+        team_name: 'McLaren',
+        team_colour: 'ff8000',
+        points: 160,
+        position: 2,
+        teammate_wins: 6,
+        teammate_losses: 5,
+        cumulative: [18, 36, 54, 80, 120, 160],
+      }),
+      driver({
+        driver_number: 81,
+        name_acronym: 'PIA',
+        full_name: 'Oscar Piastri',
+        team_name: 'McLaren',
+        team_colour: 'ff8000',
+        points: 140,
+        position: 3,
+        teammate_wins: 5,
+        teammate_losses: 6,
+        cumulative: [12, 28, 45, 70, 110, 140],
+      }),
+      driver({
+        driver_number: 11,
+        name_acronym: 'PER',
+        full_name: 'Sergio Perez',
+        team_name: 'Red Bull',
+        team_colour: '3671c6',
+        points: 60,
+        position: 4,
+        teammate_wins: 1,
+        teammate_losses: 9,
+        cumulative: [5, 12, 20, 35, 50, 60],
+      }),
+    ]
+    mockFetchHub.mockResolvedValue({ ...hub, drivers: h2hDrivers })
+    renderPage()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('champ-teammate-battles')).toBeInTheDocument()
+    })
+
+    expect(screen.getByText('Teammate battles')).toBeInTheDocument()
+    const rows = screen.getAllByTestId('teammate-h2h')
+    expect(rows).toHaveLength(2)
+    // McLaren 6–5 is closer than Red Bull 9–1 — McLaren row first.
+    expect(rows[0]).toHaveTextContent('McLaren')
+    expect(rows[0]).toHaveTextContent('6–5')
+    expect(rows[1]).toHaveTextContent('Red Bull')
+    expect(rows[1]).toHaveTextContent('9–1')
+  })
 })

frontend/src/test/ChampionshipSimulator.test.tsx

@@ -17,6 +17,7 @@ function driver(over: Partial<ChampHubDriver>): ChampHubDriver {
     poles: 0,
     form: [],
     cumulative: [],
+    round_positions: [],
     teammate_wins: 0,
     teammate_losses: 0,
     ...over,

frontend/src/test/ChapterStrip.test.tsx

@@ -0,0 +1,87 @@
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { fireEvent, render, screen } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { ChapterStrip } from '../components/ChapterStrip'
+import type { Chapter } from '../types'
+
+const chapters: Chapter[] = [
+  {
+    kind: 'start',
+    title: 'Start',
+    headline: 'Lights out — the field charges into Turn 1',
+    start_lap: 1,
+    end_lap: 1,
+    start_time: '2025-05-25T13:00:00Z',
+    end_time: '2025-05-25T13:01:00Z',
+    driver_numbers: [],
+  },
+  {
+    kind: 'safety_car',
+    title: 'Safety Car (L12-L15)',
+    headline: 'Sainz incident brings out the Safety Car — leaders dive for the pits',
+    start_lap: 12,
+    end_lap: 15,
+    start_time: '2025-05-25T13:12:00Z',
+    end_time: '2025-05-25T13:15:00Z',
+    driver_numbers: [55],
+  },
+]
+
+const tMin = new Date('2025-05-25T13:00:00Z').getTime()
+const tMax = new Date('2025-05-25T13:20:00Z').getTime()
+const tRange = tMax - tMin
+
+function renderStrip(
+  overrides: Partial<{
+    scrubTime: number | null
+    onChapterClick: (index: number, scrub: number) => void
+  }> = {},
+) {
+  const onChapterClick = overrides.onChapterClick ?? vi.fn()
+  const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+  render(
+    <QueryClientProvider client={queryClient}>
+      <ChapterStrip
+        chapters={chapters}
+        scrubTime={overrides.scrubTime ?? null}
+        tMin={tMin}
+        tRange={tRange}
+        tourActive={false}
+        tourChapterIndex={null}
+        onChapterClick={onChapterClick}
+        onTourToggle={vi.fn()}
+      />
+    </QueryClientProvider>,
+  )
+  return { onChapterClick }
+}
+
+describe('ChapterStrip', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('renders chapter headlines and lap ranges', () => {
+    renderStrip()
+    expect(screen.getByTestId('chapter-strip')).toBeInTheDocument()
+    expect(screen.getByText('Lights out — the field charges into Turn 1')).toBeInTheDocument()
+    expect(screen.getByText('L12–L15')).toBeInTheDocument()
+  })
+
+  it('highlights the active chapter from scrub time', () => {
+    const scrub = (new Date('2025-05-25T13:13:00Z').getTime() - tMin) / tRange
+    renderStrip({ scrubTime: scrub })
+    expect(screen.getByTestId('chapter-card-1')).toHaveClass('active')
+    expect(screen.getByTestId('chapter-card-0')).not.toHaveClass('active')
+  })
+
+  it('calls click handler to jump scrubber', () => {
+    const onChapterClick = vi.fn<(index: number, scrub: number) => void>()
+    renderStrip({ onChapterClick })
+    fireEvent.click(screen.getByTestId('chapter-card-1'))
+    expect(onChapterClick).toHaveBeenCalledTimes(1)
+    const [index, scrub] = onChapterClick.mock.calls[0]
+    expect(index).toBe(1)
+    expect(scrub).toBeCloseTo(0.6, 2)
+  })
+})

frontend/src/test/CommandCenterPage.test.tsx

@@ -156,6 +156,7 @@ describe('CommandCenterPage', () => {
       race_control: [],
       weather: [],
       laps: [],
+      chapters: [],
     })
   })
 

frontend/src/test/DriverProfilePage.test.tsx

@@ -0,0 +1,160 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { render, screen, waitFor } from '@testing-library/react'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { RouterProvider, createRouter, createRootRoute, createRoute } from '@tanstack/react-router'
+import { DriverProfilePage } from '../pages/DriverProfilePage'
+import type { DriverSummary } from '../types'
+
+vi.mock('../api', () => ({
+  fetchSeasons: vi.fn(),
+  fetchDriverSummary: vi.fn(),
+}))
+
+import { fetchSeasons, fetchDriverSummary } from '../api'
+
+const mockFetchSeasons = vi.mocked(fetchSeasons)
+const mockFetchSummary = vi.mocked(fetchDriverSummary)
+
+const summary: DriverSummary = {
+  season: 2025,
+  driver_number: 1,
+  name_acronym: 'VER',
+  full_name: 'Max Verstappen',
+  team_name: 'Red Bull',
+  team_colour: '3671c6',
+  headshot_url: '',
+  points: 50,
+  position: 1,
+  wins: 2,
+  podiums: 2,
+  poles: 1,
+  form: [25, 25],
+  cumulative: [25, 50],
+  round_labels: ['R1', 'R2'],
+  rounds: [
+    {
+      meeting_key: 1201,
+      meeting_name: 'Bahrain Grand Prix',
+      country_code: 'BHR',
+      country_name: 'Bahrain',
+      race_position: 1,
+      grid_position: 1,
+      quali_position: 1,
+      points: 25,
+      dnf: false,
+      dns: false,
+      dsq: false,
+    },
+    {
+      meeting_key: 1202,
+      meeting_name: 'Saudi Arabian Grand Prix',
+      country_code: 'SAU',
+      country_name: 'Saudi Arabia',
+      race_position: 1,
+      grid_position: 4,
+      quali_position: 4,
+      points: 25,
+      dnf: false,
+      dns: false,
+      dsq: false,
+    },
+  ],
+}
+
+function renderPage(props: { driverNumber: number; year?: number }) {
+  const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+  const rootRoute = createRootRoute({
+    component: () => (
+      <QueryClientProvider client={queryClient}>
+        <DriverProfilePage driverNumber={props.driverNumber} year={props.year} />
+      </QueryClientProvider>
+    ),
+  })
+  const indexRoute = createRoute({
+    getParentRoute: () => rootRoute,
+    path: '/',
+    component: () => null,
+  })
+  const router = createRouter({ routeTree: rootRoute.addChildren([indexRoute]) })
+  return render(<RouterProvider router={router} />)
+}
+
+describe('DriverProfilePage', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockFetchSeasons.mockResolvedValue([2025])
+    mockFetchSummary.mockResolvedValue(summary)
+  })
+
+  it('renders header, form, quali-vs-race, and rounds sections', async () => {
+    renderPage({ driverNumber: 1, year: 2025 })
+
+    await waitFor(() => {
+      expect(screen.getByTestId('driver-profile')).toBeInTheDocument()
+    })
+
+    // Header: identity + season stats.
+    expect(screen.getByTestId('dp-header')).toBeInTheDocument()
+    expect(screen.getByText('Max Verstappen')).toBeInTheDocument()
+    expect(screen.getByText('#1')).toBeInTheDocument()
+    expect(screen.getByText('Red Bull', { exact: false })).toBeInTheDocument()
+    // 'P1' / '50' also appear in the rounds table and chart axis.
+    expect(screen.getAllByText('P1').length).toBeGreaterThan(0)
+    expect(screen.getAllByText('50').length).toBeGreaterThan(0)
+
+    // Season form strip.
+    expect(screen.getByTestId('dp-form')).toBeInTheDocument()
+    expect(screen.getByText('Cumulative points')).toBeInTheDocument()
+
+    // Quali-vs-race chart shows the delta from the Saudi round (P4 → P1 = +3).
+    expect(screen.getByTestId('dp-quali-race')).toBeInTheDocument()
+    expect(screen.getAllByText('+3').length).toBeGreaterThan(0)
+
+    // Track-by-track table rows with flags.
+    const rounds = screen.getByTestId('dp-rounds')
+    expect(rounds).toBeInTheDocument()
+    expect(screen.getByText('Bahrain Grand Prix')).toBeInTheDocument()
+    expect(screen.getByText('Saudi Arabian Grand Prix')).toBeInTheDocument()
+    expect(rounds.textContent).toContain('🇧🇭')
+    expect(rounds.textContent).toContain('🇸🇦')
+
+    // With an explicit year, the seasons list is not needed.
+    expect(mockFetchSeasons).not.toHaveBeenCalled()
+    expect(mockFetchSummary).toHaveBeenCalledWith(1, 2025)
+  })
+
+  it('defaults to the latest season when no year is given', async () => {
+    renderPage({ driverNumber: 1 })
+
+    await waitFor(() => {
+      expect(screen.getByTestId('driver-profile')).toBeInTheDocument()
+    })
+    expect(mockFetchSummary).toHaveBeenCalledWith(1, 2025)
+  })
+
+  it('shows the API error message on failure', async () => {
+    mockFetchSummary.mockRejectedValue(new Error('API 404: Not Found'))
+    renderPage({ driverNumber: 99, year: 2025 })
+
+    await waitFor(() => {
+      expect(screen.getByText('API 404: Not Found')).toBeInTheDocument()
+    })
+  })
+
+  it('shows empty states when no rounds are completed', async () => {
+    mockFetchSummary.mockResolvedValue({
+      ...summary,
+      form: [],
+      cumulative: [],
+      round_labels: [],
+      rounds: [],
+    })
+    renderPage({ driverNumber: 1, year: 2025 })
+
+    await waitFor(() => {
+      expect(screen.getByTestId('driver-profile')).toBeInTheDocument()
+    })
+    expect(screen.getAllByText('No completed rounds yet.').length).toBe(2)
+    expect(screen.getByText('No grid-vs-finish data yet.')).toBeInTheDocument()
+  })
+})

frontend/src/test/RaceHubPage.test.tsx

@@ -155,6 +155,7 @@ const raceHub: RaceHub = {
       is_pit_out_lap: false,
     },
   ],
+  chapters: [],
 }
 
 const weekend: Weekend = {

frontend/src/test/RacePreviewPage.test.tsx

@@ -0,0 +1,277 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { render, screen, waitFor } from '@testing-library/react'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { RouterProvider, createRouter, createRootRoute, createRoute } from '@tanstack/react-router'
+import { RacePreviewPage } from '../pages/RacePreviewPage'
+import type { ChampHubDriver, ChampionshipHub, EnrichedGrid, EnrichedResult, Meeting, Session, TrackOutline } from '../types'
+
+vi.mock('../api', () => ({
+  fetchSeasons: vi.fn(),
+  fetchMeetings: vi.fn(),
+  fetchSessions: vi.fn(),
+  fetchResults: vi.fn(),
+  fetchStartingGrid: vi.fn(),
+  fetchTrackOutline: vi.fn(),
+  fetchChampionshipHub: vi.fn(),
+}))
+
+import {
+  fetchSeasons,
+  fetchMeetings,
+  fetchSessions,
+  fetchResults,
+  fetchStartingGrid,
+  fetchTrackOutline,
+  fetchChampionshipHub,
+} from '../api'
+
+const mockFetchSeasons = vi.mocked(fetchSeasons)
+const mockFetchMeetings = vi.mocked(fetchMeetings)
+const mockFetchSessions = vi.mocked(fetchSessions)
+const mockFetchResults = vi.mocked(fetchResults)
+const mockFetchStartingGrid = vi.mocked(fetchStartingGrid)
+const mockFetchTrackOutline = vi.mocked(fetchTrackOutline)
+const mockFetchChampionshipHub = vi.mocked(fetchChampionshipHub)
+
+const upcomingMeeting: Meeting = {
+  meeting_key: 100,
+  meeting_name: 'Monaco',
+  meeting_official_name: 'Monaco GP',
+  location: 'Monaco',
+  country_name: 'Monaco',
+  country_code: 'MON',
+  country_flag: '',
+  circuit_key: 10,
+  circuit_short_name: 'Monaco',
+  date_start: '2099-05-22T00:00:00+00:00',
+  date_end: '2099-05-24T23:59:59+00:00',
+  year: 2099,
+}
+
+const priorMeeting: Meeting = {
+  ...upcomingMeeting,
+  meeting_key: 90,
+  year: 2098,
+  date_start: '2098-05-22T00:00:00+00:00',
+  date_end: '2098-05-24T23:59:59+00:00',
+}
+
+const sessions: Session[] = [
+  {
+    session_key: 1,
+    session_name: 'FP1',
+    session_type: 'Practice',
+    meeting_key: 100,
+    date_start: '2099-05-22T10:00:00+00:00',
+    date_end: '2099-05-22T11:00:00+00:00',
+    gmt_offset: '02:00:00',
+  },
+  {
+    session_key: 2,
+    session_name: 'Sprint',
+    session_type: 'Sprint',
+    meeting_key: 100,
+    date_start: '2099-05-23T10:00:00+00:00',
+    date_end: '2099-05-23T11:00:00+00:00',
+    gmt_offset: '02:00:00',
+  },
+  {
+    session_key: 3,
+    session_name: 'Race',
+    session_type: 'Race',
+    meeting_key: 100,
+    date_start: '2099-05-24T13:00:00+00:00',
+    date_end: '2099-05-24T15:00:00+00:00',
+    gmt_offset: '02:00:00',
+  },
+]
+
+const priorRaceSession: Session = {
+  session_key: 50,
+  session_name: 'Race',
+  session_type: 'Race',
+  meeting_key: 90,
+  date_start: '2098-05-24T13:00:00+00:00',
+  date_end: '2098-05-24T15:00:00+00:00',
+  gmt_offset: '02:00:00',
+}
+
+const hubDriver = (over: Partial<ChampHubDriver>): ChampHubDriver => ({
+  driver_number: 1,
+  name_acronym: 'VER',
+  full_name: 'Max Verstappen',
+  team_name: 'Red Bull',
+  team_colour: '3671c6',
+  points: 200,
+  position: 1,
+  wins: 5,
+  podiums: 8,
+  poles: 4,
+  form: [25],
+  cumulative: [200],
+  round_positions: [1],
+  teammate_wins: 9,
+  teammate_losses: 1,
+  ...over,
+})
+
+const hub: ChampionshipHub = {
+  season: 2099,
+  round: 5,
+  total_rounds: 24,
+  rounds_left: 19,
+  last_race: 'Monaco GP',
+  round_labels: ['R1'],
+  drivers: [
+    hubDriver({}),
+    hubDriver({ driver_number: 4, name_acronym: 'NOR', points: 160, position: 2 }),
+    hubDriver({ driver_number: 16, name_acronym: 'LEC', points: 120, position: 3 }),
+  ],
+  teams: [],
+}
+
+const results: EnrichedResult[] = [
+  {
+    driver_number: 1,
+    position: 1,
+    name_acronym: 'VER',
+    full_name: 'Max Verstappen',
+    team_name: 'Red Bull',
+    team_colour: '3671c6',
+    dnf: false,
+    dns: false,
+    dsq: false,
+    duration: 100,
+    gap_to_leader: 0,
+    number_of_laps: 78,
+    points: 25,
+    session_key: 50,
+    meeting_key: 90,
+  },
+]
+
+const grid: EnrichedGrid[] = [
+  {
+    driver_number: 4,
+    position: 1,
+    name_acronym: 'NOR',
+    full_name: 'Lando Norris',
+    team_name: 'McLaren',
+    team_colour: 'ff8000',
+    session_key: 50,
+    meeting_key: 90,
+    lap_duration: 70,
+  },
+]
+
+const outline: TrackOutline = {
+  circuit_key: 10,
+  points: [
+    { x: 0.1, y: 0.2 },
+    { x: 0.5, y: 0.5 },
+    { x: 0.9, y: 0.8 },
+  ],
+  bounds: { minX: 0, maxX: 1, minY: 0, maxY: 1 },
+}
+
+function renderPage() {
+  const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+  const rootRoute = createRootRoute({
+    component: () => (
+      <QueryClientProvider client={queryClient}>
+        <RacePreviewPage />
+      </QueryClientProvider>
+    ),
+  })
+  const indexRoute = createRoute({ getParentRoute: () => rootRoute, path: '/', component: RacePreviewPage })
+  const router = createRouter({ routeTree: rootRoute.addChildren([indexRoute]) })
+  return render(<RouterProvider router={router} />)
+}
+
+describe('RacePreviewPage', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockFetchSeasons.mockResolvedValue([2099])
+    mockFetchChampionshipHub.mockResolvedValue(hub)
+    mockFetchTrackOutline.mockResolvedValue(outline)
+    mockFetchResults.mockResolvedValue(results)
+    mockFetchStartingGrid.mockResolvedValue(grid)
+  })
+
+  it('renders upcoming race preview with sections', async () => {
+    mockFetchMeetings.mockImplementation(async (year: number) => {
+      if (year === 2099) return [upcomingMeeting]
+      if (year === 2098) return [priorMeeting]
+      return []
+    })
+    mockFetchSessions.mockImplementation(async (meetingKey: number) => {
+      if (meetingKey === 100) return sessions
+      if (meetingKey === 90) return [priorRaceSession]
+      return []
+    })
+
+    renderPage()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('preview-page')).toBeInTheDocument()
+    })
+
+    await waitFor(() => {
+      expect(screen.getByTestId('preview-countdown')).toBeInTheDocument()
+    })
+
+    expect(screen.getByTestId('preview-header')).toHaveTextContent('Monaco')
+    expect(screen.getByTestId('preview-schedule')).toHaveTextContent('FP1')
+    expect(screen.getByTestId('preview-track-card')).toBeInTheDocument()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('preview-last-year-card')).toHaveTextContent('VER')
+    })
+
+    expect(screen.getByTestId('preview-title-fight-card')).toHaveTextContent('NOR')
+    expect(screen.getByTestId('preview-sprint-note')).toBeInTheDocument()
+  })
+
+  it('renders season-over state when no upcoming meeting', async () => {
+    mockFetchMeetings.mockResolvedValue([
+      {
+        ...upcomingMeeting,
+        date_start: '2020-05-22T00:00:00+00:00',
+        date_end: '2020-05-24T23:59:59+00:00',
+      },
+    ])
+
+    renderPage()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('preview-season-over')).toBeInTheDocument()
+    })
+
+    expect(screen.getByText('Season complete')).toBeInTheDocument()
+    expect(screen.getByTestId('preview-title-fight-card')).toBeInTheDocument()
+    expect(screen.queryByTestId('preview-header')).not.toBeInTheDocument()
+  })
+
+  it('shows first-time circuit empty state', async () => {
+    const newCircuit: Meeting = {
+      ...upcomingMeeting,
+      meeting_key: 200,
+      circuit_key: 999,
+      meeting_name: 'New GP',
+    }
+
+    mockFetchMeetings.mockImplementation(async (year: number) => {
+      if (year === 2099) return [newCircuit]
+      if (year === 2098) return [priorMeeting]
+      return []
+    })
+    mockFetchSessions.mockResolvedValue(sessions)
+    mockFetchTrackOutline.mockResolvedValue(null)
+
+    renderPage()
+
+    await waitFor(() => {
+      expect(screen.getByTestId('preview-last-year-card')).toHaveTextContent('First time on the calendar')
+    })
+  })
+})

frontend/src/test/RaceStoryCanvas.test.tsx

@@ -0,0 +1,135 @@
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { RaceStoryCanvas } from '../components/RaceStoryCanvas'
+import type { RaceHub, ReplayFramesResponse, TrackOutline } from '../types'
+
+vi.mock('../api', () => ({
+  fetchReplayFrames: vi.fn(),
+  fetchTrackOutline: vi.fn(),
+}))
+
+import { fetchReplayFrames, fetchTrackOutline } from '../api'
+
+const mockFetchReplayFrames = vi.mocked(fetchReplayFrames)
+const mockFetchTrackOutline = vi.mocked(fetchTrackOutline)
+
+const outline: TrackOutline = {
+  circuit_key: 1,
+  bounds: { minX: 0, maxX: 100, minY: 0, maxY: 100 },
+  points: [
+    { x: 0, y: 0 },
+    { x: 1, y: 0 },
+    { x: 1, y: 1 },
+  ],
+}
+
+const replay: ReplayFramesResponse = {
+  session_key: 99,
+  interval_ms: 5000,
+  start_time: '2025-05-25T13:00:00Z',
+  frames: [{ t: 0, cars: { '1': { x: 10, y: 20 } } }],
+}
+
+const raceHub: RaceHub = {
+  source: 'local',
+  session_key: 99,
+  datasets: {
+    positions: { status: 'available', source: 'local', count: 2 },
+  },
+  meeting: {
+    meeting_key: 1,
+    meeting_name: 'Monaco Grand Prix',
+    meeting_official_name: 'FORMULA 1 GRAND PRIX DE MONACO 2025',
+    location: 'Monaco',
+    country_name: 'Monaco',
+    country_code: 'MON',
+    country_flag: '',
+    circuit_key: 1,
+    circuit_short_name: 'Monaco',
+    date_start: '2025-05-23T00:00:00Z',
+    date_end: '2025-05-25T00:00:00Z',
+    year: 2025,
+  },
+  session: {
+    session_key: 99,
+    session_name: 'Race',
+    session_type: 'Race',
+    circuit_key: 1,
+    meeting_key: 1,
+    date_start: '2025-05-25T13:00:00Z',
+    date_end: '2025-05-25T15:00:00Z',
+    gmt_offset: '02:00:00',
+  },
+  drivers: [],
+  results: [
+    {
+      driver_number: 1,
+      position: 1,
+      name_acronym: 'VER',
+      full_name: 'Max Verstappen',
+      team_name: 'Red Bull Racing',
+      team_colour: '3671C6',
+      dnf: false,
+      dns: false,
+      dsq: false,
+      duration: null,
+      gap_to_leader: null,
+      number_of_laps: 78,
+      points: 25,
+      session_key: 99,
+      meeting_key: 1,
+    },
+  ],
+  starting_grid: [
+    {
+      driver_number: 1,
+      position: 1,
+      name_acronym: 'VER',
+      full_name: 'Max Verstappen',
+      team_name: 'Red Bull Racing',
+      team_colour: '3671C6',
+      session_key: 99,
+      meeting_key: 1,
+      lap_duration: null,
+    },
+  ],
+  stints: [],
+  pit_stops: [],
+  positions: [
+    { session_key: 99, driver_number: 1, meeting_key: 1, date: '2025-05-25T13:00:00Z', position: 1 },
+    { session_key: 99, driver_number: 1, meeting_key: 1, date: '2025-05-25T13:05:00Z', position: 1 },
+  ],
+  race_control: [],
+  weather: [],
+  laps: [],
+  chapters: [],
+}
+
+function renderCanvas() {
+  const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+  return render(
+    <QueryClientProvider client={queryClient}>
+      <RaceStoryCanvas data={raceHub} />
+    </QueryClientProvider>,
+  )
+}
+
+describe('RaceStoryCanvas replay map', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockFetchReplayFrames.mockResolvedValue(replay)
+    mockFetchTrackOutline.mockResolvedValue(outline)
+  })
+
+  it('fetches replay frames lazily when the map panel opens', async () => {
+    renderCanvas()
+
+    expect(mockFetchReplayFrames).not.toHaveBeenCalled()
+    fireEvent.click(screen.getByRole('button', { name: 'Map' }))
+
+    await waitFor(() => expect(mockFetchReplayFrames).toHaveBeenCalledWith(99, 5000))
+    expect(mockFetchTrackOutline).toHaveBeenCalledWith(1, 2025)
+    expect(await screen.findByTestId('replay-track-map')).toBeInTheDocument()
+  })
+})

frontend/src/test/ReplayTrackMap.test.tsx

@@ -0,0 +1,56 @@
+import { describe, expect, it } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import { ReplayTrackMap } from '../components/ReplayTrackMap'
+import type { EnrichedResult, ReplayFramesResponse, TrackOutline } from '../types'
+
+const outline: TrackOutline = {
+  circuit_key: 1,
+  bounds: { minX: 0, maxX: 100, minY: 0, maxY: 100 },
+  points: [
+    { x: 0, y: 0 },
+    { x: 1, y: 0 },
+    { x: 1, y: 1 },
+  ],
+}
+
+const replay: ReplayFramesResponse = {
+  session_key: 99,
+  interval_ms: 5000,
+  start_time: '2025-05-25T13:00:00Z',
+  frames: [
+    { t: 0, cars: { '1': { x: 0, y: 0 } } },
+    { t: 5000, cars: { '1': { x: 50, y: 50 } } },
+  ],
+}
+
+const results: EnrichedResult[] = [
+  {
+    driver_number: 1,
+    position: 1,
+    name_acronym: 'VER',
+    full_name: 'Max Verstappen',
+    team_name: 'Red Bull Racing',
+    team_colour: '3671C6',
+    dnf: false,
+    dns: false,
+    dsq: false,
+    duration: null,
+    gap_to_leader: null,
+    number_of_laps: 78,
+    points: 25,
+    session_key: 99,
+    meeting_key: 1,
+  },
+]
+
+describe('ReplayTrackMap', () => {
+  it('renders an empty state when replay frames are missing', () => {
+    render(<ReplayTrackMap outline={outline} replay={{ ...replay, frames: [] }} tMs={0} drivers={[]} results={results} />)
+    expect(screen.getByTestId('replay-track-map')).toHaveTextContent(/historical GPS unavailable/i)
+  })
+
+  it('renders car labels from result metadata', () => {
+    render(<ReplayTrackMap outline={outline} replay={replay} tMs={2500} drivers={[]} results={results} />)
+    expect(screen.getByLabelText(/VER replay position/i)).toBeInTheDocument()
+  })
+})

frontend/src/test/RivalryCompare.test.tsx

@@ -0,0 +1,114 @@
+import { describe, it, expect } from 'vitest'
+import { render, screen, fireEvent } from '@testing-library/react'
+import { RivalryCompare } from '../components/RivalryCompare'
+import type { ChampHubDriver, ChampionshipHub } from '../types'
+
+function driver(over: Partial<ChampHubDriver>): ChampHubDriver {
+  return {
+    driver_number: 1,
+    name_acronym: 'VER',
+    full_name: 'Max Verstappen',
+    team_name: 'Red Bull',
+    team_colour: '3671c6',
+    points: 100,
+    position: 1,
+    wins: 2,
+    podiums: 3,
+    poles: 1,
+    form: [25, 18, 25],
+    cumulative: [25, 43, 68],
+    round_positions: [1, 2, 1],
+    teammate_wins: 3,
+    teammate_losses: 0,
+    ...over,
+  }
+}
+
+function makeHub(drivers: ChampHubDriver[]): ChampionshipHub {
+  return {
+    season: 2025,
+    round: 3,
+    total_rounds: 10,
+    rounds_left: 7,
+    last_race: 'Japan GP',
+    round_labels: ['R1', 'R2', 'R3'],
+    drivers,
+    teams: [],
+  }
+}
+
+const hub = makeHub([
+  driver({}),
+  driver({
+    driver_number: 4,
+    name_acronym: 'NOR',
+    full_name: 'Lando Norris',
+    team_name: 'McLaren',
+    team_colour: 'ff8000',
+    points: 90,
+    position: 2,
+    cumulative: [18, 43, 61],
+    round_positions: [2, 1, 2],
+  }),
+  driver({
+    driver_number: 16,
+    name_acronym: 'LEC',
+    full_name: 'Charles Leclerc',
+    team_name: 'Ferrari',
+    team_colour: 'e8002d',
+    points: 50,
+    position: 3,
+    cumulative: [15, 28, 40],
+    round_positions: [3, 0, 3],
+  }),
+])
+
+describe('RivalryCompare', () => {
+  it('defaults to the top two drivers and shows the H2H score', () => {
+    render(<RivalryCompare hub={hub} />)
+
+    expect(screen.getByTestId('champ-view-rivalry')).toBeInTheDocument()
+    expect(screen.getByTestId('rivalry-pick-a')).toHaveValue('1')
+    expect(screen.getByTestId('rivalry-pick-b')).toHaveValue('4')
+    // VER wins R1 and R3, NOR wins R2.
+    expect(screen.getByTestId('rivalry-h2h-num')).toHaveTextContent('2–1')
+    expect(screen.getByText('3 rounds counted', { exact: false })).toBeInTheDocument()
+    expect(screen.getByTestId('rivalry-points-race')).toBeInTheDocument()
+    expect(screen.getByTestId('rivalry-gap')).toBeInTheDocument()
+    // Last gap: 68 − 61 = +7 → VER ahead.
+    expect(screen.getByText('VER leads by 7 pts', { exact: false })).toBeInTheDocument()
+  })
+
+  it('recomputes when a different driver is picked and skips missing rounds', () => {
+    render(<RivalryCompare hub={hub} />)
+
+    fireEvent.change(screen.getByTestId('rivalry-pick-b'), { target: { value: '16' } })
+
+    // VER vs LEC: R2 skipped (LEC has no position), VER wins R1 and R3.
+    expect(screen.getByTestId('rivalry-h2h-num')).toHaveTextContent('2–0')
+    expect(screen.getByText('2 rounds counted · 1 skipped', { exact: false })).toBeInTheDocument()
+  })
+
+  it('shows an empty state with fewer than two drivers', () => {
+    render(<RivalryCompare hub={makeHub([driver({})])} />)
+    expect(screen.getByTestId('champ-view-rivalry')).toHaveTextContent('at least two drivers')
+  })
+
+  it('shows an empty message when no rounds are completed', () => {
+    const empty = makeHub([
+      driver({ cumulative: [], round_positions: [], form: [] }),
+      driver({
+        driver_number: 4,
+        name_acronym: 'NOR',
+        cumulative: [],
+        round_positions: [],
+        form: [],
+      }),
+    ])
+    empty.round = 0
+    empty.round_labels = []
+
+    render(<RivalryCompare hub={empty} />)
+    expect(screen.getByTestId('champ-view-rivalry')).toHaveTextContent('No completed rounds yet')
+  })
+})

frontend/src/test/TeammateH2H.test.tsx

@@ -0,0 +1,54 @@
+import { describe, expect, it } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import { TeammateH2H } from '../components/TeammateH2H'
+
+describe('TeammateH2H', () => {
+  it('renders score and TLAs', () => {
+    render(
+      <TeammateH2H
+        teamName="Red Bull"
+        teamColour="3671c6"
+        driverATla="VER"
+        driverBTla="PER"
+        winsA={9}
+        winsB={1}
+      />,
+    )
+    expect(screen.getByText('VER')).toBeInTheDocument()
+    expect(screen.getByText('PER')).toBeInTheDocument()
+    expect(screen.getByTestId('h2h-score')).toHaveTextContent('9–1')
+    expect(screen.getByText('Red Bull')).toBeInTheDocument()
+  })
+
+  it('sets proportional bar segment widths from wins', () => {
+    render(
+      <TeammateH2H
+        teamName="McLaren"
+        teamColour="ff8000"
+        driverATla="NOR"
+        driverBTla="PIA"
+        winsA={6}
+        winsB={4}
+      />,
+    )
+    const barA = screen.getByTestId('h2h-bar-a')
+    const barB = screen.getByTestId('h2h-bar-b')
+    expect(barA).toHaveStyle({ width: '60%' })
+    expect(barB).toHaveStyle({ width: '40%' })
+  })
+
+  it('shows extra driver note when provided', () => {
+    render(
+      <TeammateH2H
+        teamName="Red Bull"
+        teamColour="3671c6"
+        driverATla="VER"
+        driverBTla="PER"
+        winsA={5}
+        winsB={3}
+        extraNote="+1"
+      />,
+    )
+    expect(screen.getByText('+1')).toBeInTheDocument()
+  })
+})

frontend/src/test/chapters.test.ts

@@ -0,0 +1,63 @@
+import { describe, expect, it } from 'vitest'
+import {
+  activeChapterIndex,
+  chapterKindLabel,
+  chapterLapRange,
+  chapterStartScrub,
+  chapterTourDurations,
+} from '../lib/chapters'
+import type { Chapter } from '../types'
+
+const sampleChapters: Chapter[] = [
+  {
+    kind: 'start',
+    title: 'Start',
+    headline: 'Lights out — the field charges into Turn 1',
+    start_lap: 1,
+    end_lap: 1,
+    start_time: '2025-05-25T13:00:00Z',
+    end_time: '2025-05-25T13:01:00Z',
+    driver_numbers: [],
+  },
+  {
+    kind: 'safety_car',
+    title: 'Safety Car (L12-L15)',
+    headline: 'Sainz incident brings out the Safety Car — leaders dive for the pits',
+    start_lap: 12,
+    end_lap: 15,
+    start_time: '2025-05-25T13:12:00Z',
+    end_time: '2025-05-25T13:15:00Z',
+    driver_numbers: [55],
+  },
+]
+
+describe('chapters lib', () => {
+  it('labels chapter kinds', () => {
+    expect(chapterKindLabel('safety_car')).toBe('SC')
+    expect(chapterKindLabel('finish')).toBe('FIN')
+  })
+
+  it('formats lap ranges', () => {
+    expect(chapterLapRange(sampleChapters[0])).toBe('L1')
+    expect(chapterLapRange(sampleChapters[1])).toBe('L12–L15')
+  })
+
+  it('maps chapter start time to scrub position', () => {
+    const tMin = new Date('2025-05-25T13:00:00Z').getTime()
+    const tMax = new Date('2025-05-25T13:20:00Z').getTime()
+    const scrub = chapterStartScrub(sampleChapters[1], tMin, tMax - tMin)
+    expect(scrub).toBeCloseTo(0.6, 2)
+  })
+
+  it('finds active chapter from scrub time', () => {
+    const tMin = new Date('2025-05-25T13:00:00Z').getTime()
+    const tMax = new Date('2025-05-25T13:20:00Z').getTime()
+    const tRange = tMax - tMin
+    const scrub = (new Date('2025-05-25T13:13:00Z').getTime() - tMin) / tRange
+    expect(activeChapterIndex(sampleChapters, scrub, tMin, tRange)).toBe(1)
+  })
+
+  it('splits 90s evenly across chapters', () => {
+    expect(chapterTourDurations(sampleChapters)).toEqual([45_000, 45_000])
+  })
+})

frontend/src/test/digest.test.ts

@@ -0,0 +1,266 @@
+import { describe, it, expect } from 'vitest'
+import {
+  activeDigestWindow,
+  filterByTag,
+  groupByWindow,
+  gpWindows,
+  itemsForWindow,
+  sinceLastLabel,
+  sortWindowBucketsNewestFirst,
+  tagItems,
+  topTags,
+  windowForDate,
+} from '../lib/digest'
+import type { ChampHubDriver, ChampHubTeam, Meeting, NewsItem } from '../types'
+
+const meeting = (overrides: Partial<Meeting> = {}): Meeting => ({
+  meeting_key: 1,
+  meeting_name: 'Bahrain',
+  meeting_official_name: 'Bahrain GP',
+  location: 'Sakhir',
+  country_name: 'Bahrain',
+  country_code: 'BRN',
+  country_flag: '',
+  circuit_short_name: 'Sakhir',
+  date_start: '2025-03-14T00:00:00+00:00',
+  date_end: '2025-03-16T23:59:59+00:00',
+  year: 2025,
+  ...overrides,
+})
+
+const news = (overrides: Partial<NewsItem> = {}): NewsItem => ({
+  source: 'autosport-f1',
+  title: 'Headline',
+  url: `https://example.com/${Math.random()}`,
+  fetched_at: '2025-04-01T12:00:00Z',
+  ...overrides,
+})
+
+const driver = (over: Partial<ChampHubDriver>): ChampHubDriver => ({
+  driver_number: 1,
+  name_acronym: 'VER',
+  full_name: 'Max Verstappen',
+  team_name: 'Red Bull',
+  team_colour: '3671c6',
+  points: 100,
+  position: 1,
+  wins: 3,
+  podiums: 5,
+  poles: 2,
+  form: [25, 18, 25],
+  cumulative: [25, 43, 68, 100],
+  teammate_wins: 4,
+  teammate_losses: 1,
+  round_positions: [],
+  ...over,
+})
+
+const team = (over: Partial<ChampHubTeam>): ChampHubTeam => ({
+  team_name: 'Red Bull',
+  team_colour: '3671c6',
+  points: 150,
+  position: 1,
+  wins: 4,
+  ...over,
+})
+
+describe('gpWindows', () => {
+  const bahrain = meeting({ meeting_key: 1, meeting_name: 'Bahrain' })
+  const monaco = meeting({
+    meeting_key: 2,
+    meeting_name: 'Monaco',
+    date_start: '2025-05-23T00:00:00+00:00',
+    date_end: '2025-05-25T23:59:59+00:00',
+  })
+  const canada = meeting({
+    meeting_key: 3,
+    meeting_name: 'Canada',
+    date_start: '2025-06-13T00:00:00+00:00',
+    date_end: '2025-06-15T23:59:59+00:00',
+  })
+
+  it('derives inter-race windows mid-season', () => {
+    const now = new Date('2025-04-10T12:00:00Z')
+    const windows = gpWindows([bahrain, monaco, canada], now)
+
+    expect(windows).toHaveLength(3)
+    expect(windows[0].start).toBeNull()
+    expect(windows[0].end?.toISOString()).toBe(new Date('2025-05-23T00:00:00+00:00').toISOString())
+    expect(windows[1].start?.toISOString()).toBe(new Date('2025-03-16T23:59:59+00:00').toISOString())
+    expect(windows[1].end?.toISOString()).toBe(new Date('2025-06-13T00:00:00+00:00').toISOString())
+    expect(windows[2].start?.toISOString()).toBe(new Date('2025-05-25T23:59:59+00:00').toISOString())
+    expect(windows[2].end).toBeNull()
+  })
+
+  it('handles before the first race of the season', () => {
+    const now = new Date('2025-01-01T00:00:00Z')
+    const windows = gpWindows([bahrain, monaco], now)
+    expect(windows[0].start).toBeNull()
+    expect(activeDigestWindow(windows, [bahrain, monaco], now)?.meeting_name).toBe('Bahrain')
+    expect(sinceLastLabel([bahrain, monaco], now)).toBe('Before Bahrain')
+  })
+
+  it('handles after the final race of the season', () => {
+    const now = new Date('2025-12-01T00:00:00Z')
+    const windows = gpWindows([bahrain, monaco], now)
+    expect(activeDigestWindow(windows, [bahrain, monaco], now)?.meeting_name).toBe('Monaco')
+    expect(sinceLastLabel([bahrain, monaco], now)).toBe('Monaco')
+    expect(windows[1].end).toBeNull()
+  })
+})
+
+describe('groupByWindow', () => {
+  const bahrain = meeting({ meeting_key: 1 })
+  const monaco = meeting({
+    meeting_key: 2,
+    date_start: '2025-05-23T00:00:00+00:00',
+    date_end: '2025-05-25T23:59:59+00:00',
+  })
+  const windows = gpWindows([bahrain, monaco], new Date('2025-04-10T12:00:00Z'))
+
+  it('buckets dated items into the matching GP window', () => {
+    const items = [
+      news({ url: 'https://a', published_at: '2025-03-10T10:00:00Z', title: 'Pre-Bahrain' }),
+      news({ url: 'https://b', published_at: '2025-04-05T10:00:00Z', title: 'Between races' }),
+      news({ url: 'https://c', published_at: '2025-05-24T10:00:00Z', title: 'Monaco weekend' }),
+    ]
+
+    const grouped = groupByWindow(items, windows)
+    const bahrainItems = grouped.windows.find((entry) => entry.window.meeting_key === 1)?.items ?? []
+    const monacoItems = grouped.windows.find((entry) => entry.window.meeting_key === 2)?.items ?? []
+
+    expect(bahrainItems).toHaveLength(1)
+    expect(bahrainItems[0].title).toBe('Pre-Bahrain')
+    expect(monacoItems).toHaveLength(2)
+    expect(monacoItems.map((item) => item.title)).toEqual(['Between races', 'Monaco weekend'])
+  })
+
+  it('puts undated items in the recent bucket', () => {
+    const items = [
+      news({ url: 'https://u', title: 'Undated story' }),
+      news({ url: 'https://d', published_at: '2025-04-05T10:00:00Z' }),
+    ]
+    const grouped = groupByWindow(items, windows)
+    expect(grouped.recent).toHaveLength(1)
+    expect(grouped.recent[0].url).toBe('https://u')
+  })
+
+  it('sorts window buckets newest first for display', () => {
+    const items = [
+      news({ published_at: '2025-03-10T10:00:00Z' }),
+      news({ published_at: '2025-05-24T10:00:00Z' }),
+    ]
+    const grouped = groupByWindow(items, windows)
+    const sorted = sortWindowBucketsNewestFirst(grouped.windows)
+    expect(sorted[0].window.meeting_key).toBe(2)
+    expect(sorted[1].window.meeting_key).toBe(1)
+  })
+})
+
+describe('tagItems', () => {
+  const drivers = [
+    driver({ name_acronym: 'VER', full_name: 'Max Verstappen', team_name: 'Red Bull' }),
+    driver({
+      driver_number: 4,
+      name_acronym: 'NOR',
+      full_name: 'Lando Norris',
+      team_name: 'McLaren',
+      team_colour: 'ff8000',
+    }),
+  ]
+  const teams = [
+    team({ team_name: 'Red Bull' }),
+    team({ team_name: 'McLaren', team_colour: 'ff8000' }),
+  ]
+
+  it('tags drivers and teams case-insensitively', () => {
+    const [item] = tagItems(
+      [news({ title: 'ver leads mclaren in practice', summary: 'Norris close behind' })],
+      drivers,
+      teams,
+    )
+    const labels = item.tags.map((tag) => tag.label).sort()
+    expect(labels).toEqual(['McLaren', 'NOR', 'VER'])
+  })
+
+  it('returns no tags when nothing matches', () => {
+    const [item] = tagItems(
+      [news({ title: 'Generic paddock update' })],
+      drivers,
+      teams,
+    )
+    expect(item.tags).toEqual([])
+  })
+
+  it('prefers the longest overlapping match', () => {
+    const [item] = tagItems(
+      [news({ title: 'Max Verstappen extends championship lead' })],
+      drivers,
+      teams,
+    )
+    expect(item.tags).toHaveLength(1)
+    expect(item.tags[0].label).toBe('VER')
+  })
+
+  it('matches a driver last name inside prose', () => {
+    const [item] = tagItems(
+      [news({ title: 'Verstappen was untouchable in qualifying' })],
+      drivers,
+      teams,
+    )
+    expect(item.tags.some((tag) => tag.label === 'VER')).toBe(true)
+  })
+})
+
+describe('digest helpers', () => {
+  it('collects top tags by frequency', () => {
+    const tagged = tagItems(
+      [
+        news({ title: 'VER wins', url: 'https://a' }),
+        news({ title: 'VER dominates', url: 'https://b' }),
+        news({ title: 'Norris podium', url: 'https://c' }),
+      ],
+      [driver({}), driver({ driver_number: 4, name_acronym: 'NOR', full_name: 'Lando Norris', team_name: 'McLaren' })],
+      [team({}), team({ team_name: 'McLaren', team_colour: 'ff8000' })],
+    )
+    expect(topTags(tagged, 2).map((tag) => tag.label)).toEqual(['VER', 'NOR'])
+  })
+
+  it('filters items by tag key', () => {
+    const tagged = tagItems(
+      [
+        news({ title: 'VER wins', url: 'https://a' }),
+        news({ title: 'Neutral headline', url: 'https://b' }),
+      ],
+      [driver({})],
+      [team({})],
+    )
+    const filtered = filterByTag(tagged, 'driver:VER')
+    expect(filtered).toHaveLength(1)
+    expect(filtered[0].url).toBe('https://a')
+  })
+
+  it('selects items for the active digest window', () => {
+    const bahrain = meeting({ meeting_key: 1 })
+    const monaco = meeting({
+      meeting_key: 2,
+      date_start: '2025-05-23T00:00:00+00:00',
+      date_end: '2025-05-25T23:59:59+00:00',
+    })
+    const now = new Date('2025-04-10T12:00:00Z')
+    const windows = gpWindows([bahrain, monaco], now)
+    const active = activeDigestWindow(windows, [bahrain, monaco], now)
+    const tagged = tagItems(
+      [
+        news({ published_at: '2025-04-05T10:00:00Z', url: 'https://in' }),
+        news({ published_at: '2025-03-10T10:00:00Z', url: 'https://out' }),
+      ],
+      [],
+      [],
+    )
+    const inWindow = itemsForWindow(tagged, active)
+    expect(inWindow).toHaveLength(1)
+    expect(inWindow[0].url).toBe('https://in')
+    expect(windowForDate(windows, new Date('2025-04-05T10:00:00Z'))?.meeting_key).toBe(2)
+  })
+})

frontend/src/test/driverProfile.test.ts

@@ -0,0 +1,104 @@
+import { describe, it, expect } from 'vitest'
+import {
+  formatDelta,
+  formatPosition,
+  gridFinishDeltas,
+  shortGpLabel,
+} from '../lib/driverProfile'
+import type { DriverSummaryRound } from '../types'
+
+function round(over: Partial<DriverSummaryRound>): DriverSummaryRound {
+  return {
+    meeting_key: 1201,
+    meeting_name: 'Bahrain Grand Prix',
+    country_code: 'BHR',
+    country_name: 'Bahrain',
+    race_position: 1,
+    grid_position: 1,
+    quali_position: 1,
+    points: 25,
+    dnf: false,
+    dns: false,
+    dsq: false,
+    ...over,
+  }
+}
+
+describe('gridFinishDeltas', () => {
+  it('computes positive delta for places gained', () => {
+    const [d] = gridFinishDeltas([round({ grid_position: 5, race_position: 2, points: 18 })])
+    expect(d.grid).toBe(5)
+    expect(d.finish).toBe(2)
+    expect(d.delta).toBe(3)
+    expect(d.points).toBe(18)
+    expect(d.status).toBe('classified')
+    expect(d.round).toBe(1)
+  })
+
+  it('computes negative delta for places lost', () => {
+    const [d] = gridFinishDeltas([round({ grid_position: 1, race_position: 4 })])
+    expect(d.delta).toBe(-3)
+  })
+
+  it('returns null delta when the grid slot is unknown (position 0)', () => {
+    const [d] = gridFinishDeltas([round({ grid_position: 0, race_position: 6 })])
+    expect(d.grid).toBeNull()
+    expect(d.finish).toBe(6)
+    expect(d.delta).toBeNull()
+  })
+
+  it('flags DNS rounds and never computes a delta for them', () => {
+    const [d] = gridFinishDeltas([round({ dns: true, grid_position: 8, race_position: 0 })])
+    expect(d.status).toBe('dns')
+    expect(d.delta).toBeNull()
+  })
+
+  it('marks rounds the driver did not enter as absent', () => {
+    const [d] = gridFinishDeltas([round({ grid_position: 0, race_position: 0, points: 0 })])
+    expect(d.status).toBe('absent')
+    expect(d.grid).toBeNull()
+    expect(d.finish).toBeNull()
+    expect(d.delta).toBeNull()
+  })
+
+  it('still computes the delta for a classified DNF with known positions', () => {
+    const [d] = gridFinishDeltas([round({ dnf: true, grid_position: 3, race_position: 15 })])
+    expect(d.status).toBe('dnf')
+    expect(d.delta).toBe(-12)
+  })
+
+  it('numbers rounds sequentially and shortens labels', () => {
+    const ds = gridFinishDeltas([
+      round({}),
+      round({ meeting_name: 'Saudi Arabian Grand Prix', meeting_key: 1202 }),
+    ])
+    expect(ds.map((d) => d.round)).toEqual([1, 2])
+    expect(ds[1].label).toBe('Saudi Arabian')
+  })
+})
+
+describe('shortGpLabel', () => {
+  it('strips "Grand Prix" wherever it appears', () => {
+    expect(shortGpLabel('Bahrain Grand Prix')).toBe('Bahrain')
+    expect(shortGpLabel('Grand Prix of Monaco')).toBe('of Monaco')
+  })
+
+  it('falls back to the original name when stripping empties it', () => {
+    expect(shortGpLabel('Grand Prix')).toBe('Grand Prix')
+  })
+})
+
+describe('formatPosition / formatDelta', () => {
+  it('formats positions', () => {
+    expect(formatPosition(4)).toBe('P4')
+    expect(formatPosition(null)).toBe('—')
+    expect(formatPosition(0)).toBe('—')
+  })
+
+  it('formats deltas', () => {
+    expect(formatDelta(3)).toBe('+3')
+    expect(formatDelta(-2)).toBe('−2')
+    expect(formatDelta(0)).toBe('=')
+    expect(formatDelta(null)).toBe('—')
+  })
+})

frontend/src/test/h2h.test.ts

@@ -0,0 +1,133 @@
+import { describe, expect, it } from 'vitest'
+import { teammatePairs } from '../lib/h2h'
+import type { ChampHubDriver } from '../types'
+
+function driver(over: Partial<ChampHubDriver>): ChampHubDriver {
+  return {
+    driver_number: 1,
+    name_acronym: 'VER',
+    full_name: 'Max Verstappen',
+    team_name: 'Red Bull',
+    team_colour: '3671c6',
+    points: 200,
+    position: 1,
+    wins: 5,
+    podiums: 8,
+    poles: 4,
+    form: [],
+    cumulative: [],
+    teammate_wins: 9,
+    teammate_losses: 1,
+    round_positions: [],
+    ...over,
+  }
+}
+
+describe('teammatePairs', () => {
+  it('returns empty for no drivers', () => {
+    expect(teammatePairs([])).toEqual([])
+  })
+
+  it('skips teams with a single driver', () => {
+    const drivers = [
+      driver({ driver_number: 1, team_name: 'Red Bull' }),
+      driver({ driver_number: 44, name_acronym: 'HAM', team_name: 'Mercedes', points: 50 }),
+    ]
+    expect(teammatePairs(drivers)).toHaveLength(0)
+  })
+
+  it('pairs two-driver teams', () => {
+    const drivers = [
+      driver({ driver_number: 1, name_acronym: 'VER', points: 200, teammate_wins: 9, teammate_losses: 1 }),
+      driver({
+        driver_number: 11,
+        name_acronym: 'PER',
+        full_name: 'Sergio Perez',
+        points: 60,
+        teammate_wins: 1,
+        teammate_losses: 9,
+      }),
+    ]
+    const pairs = teammatePairs(drivers)
+    expect(pairs).toHaveLength(1)
+    expect(pairs[0].teamName).toBe('Red Bull')
+    expect(pairs[0].driverA.name_acronym).toBe('VER')
+    expect(pairs[0].driverB.name_acronym).toBe('PER')
+    expect(pairs[0].extraCount).toBe(0)
+    expect(pairs[0].closeness).toBe(8)
+  })
+
+  it('uses top two by points for teams with 3+ drivers', () => {
+    const drivers = [
+      driver({ driver_number: 1, name_acronym: 'VER', team_name: 'Red Bull', points: 200 }),
+      driver({
+        driver_number: 11,
+        name_acronym: 'PER',
+        team_name: 'Red Bull',
+        points: 60,
+        teammate_wins: 1,
+        teammate_losses: 9,
+      }),
+      driver({
+        driver_number: 99,
+        name_acronym: 'LAW',
+        full_name: 'Liam Lawson',
+        team_name: 'Red Bull',
+        points: 10,
+        teammate_wins: 0,
+        teammate_losses: 0,
+      }),
+    ]
+    const pairs = teammatePairs(drivers)
+    expect(pairs).toHaveLength(1)
+    expect(pairs[0].driverA.name_acronym).toBe('VER')
+    expect(pairs[0].driverB.name_acronym).toBe('PER')
+    expect(pairs[0].extraCount).toBe(1)
+  })
+
+  it('sorts by closest battle first', () => {
+    const drivers = [
+      driver({
+        driver_number: 1,
+        name_acronym: 'VER',
+        team_name: 'Red Bull',
+        points: 200,
+        teammate_wins: 10,
+        teammate_losses: 0,
+      }),
+      driver({
+        driver_number: 11,
+        name_acronym: 'PER',
+        team_name: 'Red Bull',
+        points: 60,
+        teammate_wins: 0,
+        teammate_losses: 10,
+      }),
+      driver({
+        driver_number: 4,
+        name_acronym: 'NOR',
+        team_name: 'McLaren',
+        team_colour: 'ff8000',
+        points: 160,
+        teammate_wins: 6,
+        teammate_losses: 5,
+      }),
+      driver({
+        driver_number: 81,
+        name_acronym: 'PIA',
+        full_name: 'Oscar Piastri',
+        team_name: 'McLaren',
+        team_colour: 'ff8000',
+        points: 140,
+        teammate_wins: 5,
+        teammate_losses: 6,
+      }),
+    ]
+    const pairs = teammatePairs(drivers)
+    expect(pairs).toHaveLength(2)
+    expect(pairs[0].teamName).toBe('McLaren')
+    expect(pairs[0].closeness).toBe(1)
+    expect(pairs[1].teamName).toBe('Red Bull')
+    expect(pairs[1].closeness).toBe(10)
+  })
+})

frontend/src/test/preview.test.ts

@@ -0,0 +1,227 @@
+import { describe, it, expect } from 'vitest'
+import type { ChampHubDriver, ChampionshipHub, EnrichedGrid, EnrichedResult, Meeting, Session } from '../types'
+import {
+  buildTitleFightContext,
+  countdownTargetSession,
+  extractPodium,
+  extractPole,
+  findPriorYearMeetingByCircuit,
+  findRaceSession,
+  formatPointsGap,
+  isSprintWeekend,
+  pickPreviewMeeting,
+  RACE_WIN_POINTS,
+  SPRINT_WEEKEND_MAX_POINTS,
+} from '../lib/preview'
+
+const meeting = (overrides: Partial<Meeting> = {}): Meeting => ({
+  meeting_key: 1,
+  meeting_name: 'Monaco',
+  meeting_official_name: 'Monaco GP',
+  location: 'Monaco',
+  country_name: 'Monaco',
+  country_code: 'MON',
+  country_flag: '',
+  circuit_key: 10,
+  circuit_short_name: 'Monaco',
+  date_start: '2026-05-22T00:00:00+00:00',
+  date_end: '2026-05-24T23:59:59+00:00',
+  year: 2026,
+  ...overrides,
+})
+
+const session = (overrides: Partial<Session> = {}): Session => ({
+  session_key: 100,
+  session_name: 'Race',
+  session_type: 'Race',
+  meeting_key: 1,
+  date_start: '2026-05-24T13:00:00+00:00',
+  date_end: '2026-05-24T15:00:00+00:00',
+  gmt_offset: '02:00:00',
+  ...overrides,
+})
+
+const hubDriver = (over: Partial<ChampHubDriver>): ChampHubDriver => ({
+  driver_number: 1,
+  name_acronym: 'VER',
+  full_name: 'Max Verstappen',
+  team_name: 'Red Bull',
+  team_colour: '3671c6',
+  points: 200,
+  position: 1,
+  wins: 5,
+  podiums: 8,
+  poles: 4,
+  form: [25],
+  cumulative: [200],
+  round_positions: [1],
+  teammate_wins: 9,
+  teammate_losses: 1,
+  ...over,
+})
+
+describe('preview lib', () => {
+  it('picks the next upcoming meeting', () => {
+    const now = new Date('2026-01-01T00:00:00Z')
+    const meetings = [
+      meeting({ meeting_key: 1, date_start: '2026-05-22T00:00:00+00:00' }),
+      meeting({ meeting_key: 2, meeting_name: 'Spain', date_start: '2026-06-12T00:00:00+00:00' }),
+    ]
+    expect(pickPreviewMeeting(meetings, now)?.meeting_key).toBe(1)
+  })
+
+  it('returns null when no upcoming meeting exists', () => {
+    const now = new Date('2027-01-01T00:00:00Z')
+    const meetings = [meeting({ date_start: '2026-05-22T00:00:00+00:00' })]
+    expect(pickPreviewMeeting(meetings, now)).toBeNull()
+  })
+
+  it('skips cancelled meetings', () => {
+    const now = new Date('2026-01-01T00:00:00Z')
+    const meetings = [meeting({ is_cancelled: true })]
+    expect(pickPreviewMeeting(meetings, now)).toBeNull()
+  })
+
+  it('matches prior-year meeting by circuit_key', () => {
+    const prior = [
+      meeting({ meeting_key: 50, year: 2025, circuit_key: 10 }),
+      meeting({ meeting_key: 51, year: 2025, circuit_key: 20, meeting_name: 'Spain' }),
+    ]
+    expect(findPriorYearMeetingByCircuit(prior, 10)?.meeting_key).toBe(50)
+    expect(findPriorYearMeetingByCircuit(prior, 99)).toBeNull()
+    expect(findPriorYearMeetingByCircuit(prior, undefined)).toBeNull()
+  })
+
+  it('finds the grand prix race session', () => {
+    const sessions = [
+      session({ session_key: 1, session_name: 'FP1', session_type: 'Practice', date_start: '2026-05-22T10:00:00+00:00' }),
+      session({ session_key: 2, session_name: 'Sprint', session_type: 'Sprint', date_start: '2026-05-23T10:00:00+00:00' }),
+      session({ session_key: 3, session_name: 'Race', session_type: 'Race', date_start: '2026-05-24T13:00:00+00:00' }),
+    ]
+    expect(findRaceSession(sessions)?.session_key).toBe(3)
+  })
+
+  it('detects sprint weekends', () => {
+    const sprint = [
+      session({ session_type: 'Practice' }),
+      session({ session_name: 'Sprint', session_type: 'Sprint' }),
+      session({ session_type: 'Race' }),
+    ]
+    const normal = [session({ session_type: 'Practice' }), session({ session_type: 'Race' })]
+    expect(isSprintWeekend(sprint)).toBe(true)
+    expect(isSprintWeekend(normal)).toBe(false)
+  })
+
+  it('extracts podium and pole', () => {
+    const results: EnrichedResult[] = [
+      {
+        driver_number: 1,
+        position: 1,
+        name_acronym: 'VER',
+        full_name: 'Max Verstappen',
+        team_name: 'Red Bull',
+        team_colour: '3671c6',
+        dnf: false,
+        dns: false,
+        dsq: false,
+        duration: 100,
+        gap_to_leader: 0,
+        number_of_laps: 78,
+        points: 25,
+        session_key: 1,
+        meeting_key: 1,
+      },
+      {
+        driver_number: 4,
+        position: 2,
+        name_acronym: 'NOR',
+        full_name: 'Lando Norris',
+        team_name: 'McLaren',
+        team_colour: 'ff8000',
+        dnf: false,
+        dns: false,
+        dsq: false,
+        duration: 101,
+        gap_to_leader: 1,
+        number_of_laps: 78,
+        points: 18,
+        session_key: 1,
+        meeting_key: 1,
+      },
+      {
+        driver_number: 16,
+        position: 3,
+        name_acronym: 'LEC',
+        full_name: 'Charles Leclerc',
+        team_name: 'Ferrari',
+        team_colour: 'e8002d',
+        dnf: false,
+        dns: false,
+        dsq: false,
+        duration: 102,
+        gap_to_leader: 2,
+        number_of_laps: 78,
+        points: 15,
+        session_key: 1,
+        meeting_key: 1,
+      },
+    ]
+
+    const grid: EnrichedGrid[] = [
+      {
+        driver_number: 4,
+        position: 1,
+        name_acronym: 'NOR',
+        full_name: 'Lando Norris',
+        team_name: 'McLaren',
+        team_colour: 'ff8000',
+        session_key: 1,
+        meeting_key: 1,
+        lap_duration: 70,
+      },
+    ]
+
+    const podium = extractPodium(results)
+    expect(podium.map((p) => p.name_acronym)).toEqual(['VER', 'NOR', 'LEC'])
+    expect(extractPole(grid)?.name_acronym).toBe('NOR')
+  })
+
+  it('builds title fight gaps for top 3', () => {
+    const hub: ChampionshipHub = {
+      season: 2026,
+      round: 5,
+      total_rounds: 24,
+      rounds_left: 19,
+      last_race: 'Monaco GP',
+      round_labels: ['R1'],
+      drivers: [
+        hubDriver({ points: 200, position: 1 }),
+        hubDriver({ driver_number: 4, name_acronym: 'NOR', points: 160, position: 2 }),
+        hubDriver({ driver_number: 16, name_acronym: 'LEC', points: 120, position: 3 }),
+      ],
+      teams: [],
+    }
+
+    const rows = buildTitleFightContext(hub)
+    expect(rows).toHaveLength(3)
+    expect(rows[0].gapToLeader).toBe(0)
+    expect(rows[1].gapToLeader).toBe(40)
+    expect(rows[1].gapAfterRaceWin).toBe(15)
+    expect(rows[2].gapAfterSprintWeekendMax).toBe(200 - (120 + SPRINT_WEEKEND_MAX_POINTS))
+    expect(RACE_WIN_POINTS).toBe(25)
+  })
+
+  it('formats points gaps', () => {
+    expect(formatPointsGap(0)).toBe('LEADER')
+    expect(formatPointsGap(40)).toBe('+40')
+  })
+
+  it('picks countdown target as next future session', () => {
+    const sessions = [
+      session({ session_key: 1, session_name: 'FP1', session_type: 'Practice', date_start: '2026-05-22T10:00:00+00:00', date_end: '2026-05-22T11:00:00+00:00' }),
+      session({ session_key: 2, session_name: 'Race', session_type: 'Race', date_start: '2026-05-24T13:00:00+00:00', date_end: '2026-05-24T15:00:00+00:00' }),
+    ]
+    const now = new Date('2026-05-23T12:00:00Z')
+    expect(countdownTargetSession(sessions, now)?.session_key).toBe(2)
+  })
+})

frontend/src/test/replay.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, it } from 'vitest'
+import type { ReplayFrame, TrackBounds } from '../types'
+import { interpolateReplayCars, lookupReplayFramePair, replayCarToSvg } from '../lib/replay'
+
+const frames: ReplayFrame[] = [
+  { t: 0, cars: { '1': { x: 0, y: 0 } } },
+  { t: 5000, cars: { '1': { x: 10, y: 20 }, '4': { x: 40, y: 80 } } },
+  { t: 10000, cars: { '1': { x: 20, y: 40 } } },
+]
+
+describe('replay helpers', () => {
+  it('looks up boundary frame pairs', () => {
+    expect(lookupReplayFramePair(frames, -1)).toEqual({ previous: frames[0], next: frames[0] })
+    expect(lookupReplayFramePair(frames, 10000)).toEqual({ previous: frames[2], next: frames[2] })
+    expect(lookupReplayFramePair([], 1000)).toEqual({ previous: null, next: null })
+  })
+
+  it('interpolates cars between frames and keeps one-sided samples visible', () => {
+    const cars = interpolateReplayCars(frames, 2500)
+    expect(cars['1']).toEqual({ x: 5, y: 10 })
+    expect(cars['4']).toEqual({ x: 40, y: 80 })
+  })
+
+  it('clamps interpolation outside the replay range', () => {
+    expect(interpolateReplayCars(frames, -500)['1']).toEqual({ x: 0, y: 0 })
+    expect(interpolateReplayCars(frames, 12000)['1']).toEqual({ x: 20, y: 40 })
+  })
+
+  it('maps replay GPS through the shared track-map coordinate transform', () => {
+    const bounds: TrackBounds = { minX: 0, maxX: 100, minY: 0, maxY: 200 }
+    expect(replayCarToSvg({ x: 50, y: 50 }, bounds)).toEqual({ x: 50, y: 75 })
+  })
+})

frontend/src/test/rivalry.test.ts

@@ -0,0 +1,71 @@
+import { describe, it, expect } from 'vitest'
+import { gapSeries, h2hTally, lastRounds } from '../lib/rivalry'
+
+describe('gapSeries', () => {
+  it('computes per-round a − b', () => {
+    expect(gapSeries([25, 43, 68], [18, 36, 54])).toEqual([7, 7, 14])
+  })
+
+  it('handles negative gaps (b ahead)', () => {
+    expect(gapSeries([10, 20], [18, 36])).toEqual([-8, -16])
+  })
+
+  it('truncates to the shorter series', () => {
+    expect(gapSeries([25, 43, 68], [18])).toEqual([7])
+    expect(gapSeries([], [18, 36])).toEqual([])
+  })
+})
+
+describe('h2hTally', () => {
+  it('tallies lower-position wins per round', () => {
+    const t = h2hTally([1, 2, 1], [2, 1, 3], ['R1', 'R2', 'R3'])
+    expect(t.a).toBe(2)
+    expect(t.b).toBe(1)
+    expect(t.skipped).toBe(0)
+    expect(t.rounds.map((r) => r.winner)).toEqual(['a', 'b', 'a'])
+    expect(t.rounds[0]).toEqual({ round: 1, label: 'R1', posA: 1, posB: 2, winner: 'a' })
+  })
+
+  it('skips rounds where either driver has no position', () => {
+    // R2: a missing (0). R3: b missing (0). Only R1 and R4 count.
+    const t = h2hTally([1, 0, 5, 3], [4, 2, 0, 1], ['R1', 'R2', 'R3', 'R4'])
+    expect(t.a).toBe(1)
+    expect(t.b).toBe(1)
+    expect(t.skipped).toBe(2)
+    expect(t.rounds.map((r) => r.round)).toEqual([1, 4])
+  })
+
+  it('handles arrays of different lengths (missing tail = skipped)', () => {
+    const t = h2hTally([1, 2, 3], [2], ['R1', 'R2', 'R3'])
+    expect(t.a).toBe(1)
+    expect(t.b).toBe(0)
+    expect(t.skipped).toBe(2)
+  })
+
+  it('skips equal positions defensively and falls back on labels', () => {
+    const t = h2hTally([2, 1], [2, 3], ['R1'])
+    expect(t.a).toBe(1)
+    expect(t.b).toBe(0)
+    expect(t.skipped).toBe(1)
+    expect(t.rounds[0].label).toBe('R2')
+  })
+
+  it('returns an empty tally for empty inputs', () => {
+    const t = h2hTally([], [], [])
+    expect(t).toEqual({ a: 0, b: 0, rounds: [], skipped: 0 })
+  })
+})
+
+describe('lastRounds', () => {
+  it('returns the last n counted rounds in order', () => {
+    const t = h2hTally([1, 1, 1, 2, 1, 1, 2], [2, 2, 2, 1, 2, 2, 1], [])
+    const last = lastRounds(t, 5)
+    expect(last).toHaveLength(5)
+    expect(last.map((r) => r.round)).toEqual([3, 4, 5, 6, 7])
+  })
+
+  it('returns fewer when the tally has fewer counted rounds', () => {
+    const t = h2hTally([1, 0], [2, 0], [])
+    expect(lastRounds(t, 5)).toHaveLength(1)
+  })
+})

frontend/src/test/simulator.test.ts

@@ -29,6 +29,7 @@ function driver(over: Partial<ChampHubDriver>): ChampHubDriver {
     poles: 0,
     form: [],
     cumulative: [],
+    round_positions: [],
     teammate_wins: 0,
     teammate_losses: 0,
     ...over,

frontend/src/types.ts

@@ -12,6 +12,7 @@ export interface Meeting {
   country_name: string
   country_code: string
   country_flag: string
+  circuit_key?: number
   circuit_short_name: string
   date_start: string
   date_end: string
@@ -23,6 +24,7 @@ export interface Session {
   session_key: number
   session_name: string
   session_type: string
+  circuit_key?: number
   meeting_key: number
   date_start: string
   date_end: string
@@ -89,6 +91,18 @@ export interface RaceHub {
   race_control: RaceControlMessage[]
   weather: WeatherSample[]
   laps: Lap[]
+  chapters: Chapter[]
+}
+
+export interface Chapter {
+  kind: 'start' | 'safety_car' | 'virtual_safety_car' | 'red_flag' | 'pit_phase' | 'decisive_swing' | 'finish' | string
+  title: string
+  headline: string
+  start_lap: number
+  end_lap: number
+  start_time?: string
+  end_time?: string
+  driver_numbers: number[]
 }
 
 export interface Stint {
@@ -347,6 +361,23 @@ export interface TrackOutline {
   bounds: TrackBounds
 }
 
+export interface ReplayCarPosition {
+  x: number
+  y: number
+}
+
+export interface ReplayFrame {
+  t: number
+  cars: Record<string, ReplayCarPosition>
+}
+
+export interface ReplayFramesResponse {
+  session_key: number
+  interval_ms: number
+  start_time: string
+  frames: ReplayFrame[]
+}
+
 export interface ChampHubDriver {
   driver_number: number
   name_acronym: string
@@ -360,6 +391,7 @@ export interface ChampHubDriver {
   poles: number
   form: number[]
   cumulative: number[]
+  round_positions: number[]
   teammate_wins: number
   teammate_losses: number
 }
@@ -383,6 +415,39 @@ export interface ChampionshipHub {
   teams: ChampHubTeam[]
 }
 
+export interface DriverSummaryRound {
+  meeting_key: number
+  meeting_name: string
+  country_code: string
+  country_name: string
+  race_position: number
+  grid_position: number
+  quali_position?: number
+  points: number
+  dnf: boolean
+  dns: boolean
+  dsq: boolean
+}
+
+export interface DriverSummary {
+  season: number
+  driver_number: number
+  name_acronym: string
+  full_name: string
+  team_name: string
+  team_colour: string
+  headshot_url: string
+  points: number
+  position: number
+  wins: number
+  podiums: number
+  poles: number
+  form: number[]
+  cumulative: number[]
+  round_labels: string[]
+  rounds: DriverSummaryRound[]
+}
+
 export interface NewsItem {
   source: string
   title: string

internal/chapters/chapters.go

@@ -0,0 +1,629 @@
+package chapters
+
+import (
+	"fmt"
+	"math"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/AmanTahiliani/box-box/internal/models"
+)
+
+const (
+	KindStart            = "start"
+	KindSafetyCar        = "safety_car"
+	KindVirtualSafetyCar = "virtual_safety_car"
+	KindRedFlag          = "red_flag"
+	KindPitPhase         = "pit_phase"
+	KindDecisiveSwing    = "decisive_swing"
+	KindFinish           = "finish"
+
+	pitPhaseWindowLaps = 3
+	pitPhaseShare      = 0.30
+	minPitPhaseStops   = 2
+	maxDecisiveSwings  = 3
+	decisiveAfterLap   = 5
+	structuralPriority = 110
+	flagPriority       = 100
+	pitPhasePriority   = 50
+	decisivePriority   = 40
+)
+
+type RaceControl = models.RaceControl
+type PositionSample = models.Position
+type Lap = models.Lap
+
+// Chapter is a deterministic replay segment derived from timing and race-control data.
+type Chapter struct {
+	Kind          string `json:"kind"`
+	Title         string `json:"title"`
+	Headline      string `json:"headline"`
+	StartLap      int    `json:"start_lap"`
+	EndLap        int    `json:"end_lap"`
+	StartTime     string `json:"start_time,omitempty"`
+	EndTime       string `json:"end_time,omitempty"`
+	DriverNumbers []int  `json:"driver_numbers"`
+}
+
+// Detect builds replay chapters from already-loaded race-hub datasets.
+func Detect(rc []RaceControl, positions []PositionSample, laps []Lap, totalLaps int) []Chapter {
+	totalLaps = normalizeTotalLaps(totalLaps, laps, rc)
+	if totalLaps <= 0 && len(rc) == 0 && len(positions) == 0 && len(laps) == 0 {
+		return []Chapter{}
+	}
+	if totalLaps <= 0 {
+		totalLaps = 1
+	}
+
+	lapIndex := buildLapIndex(laps)
+	chapters := []Chapter{
+		{
+			Kind:      KindStart,
+			Title:     "Start",
+			StartLap:  1,
+			EndLap:    minInt(1, totalLaps),
+			StartTime: lapIndex.lapStart(1),
+			EndTime:   lapIndex.lapEnd(1),
+		},
+	}
+	chapters = append(chapters, detectFlagPeriods(rc, lapIndex, totalLaps)...)
+	chapters = append(chapters, detectPitPhases(laps, lapIndex)...)
+	chapters = append(chapters, detectDecisiveSwings(positions, lapIndex, totalLaps)...)
+	chapters = append(chapters, detectFinish(rc, lapIndex, totalLaps))
+
+	return resolveConflicts(chapters)
+}
+
+func normalizeTotalLaps(totalLaps int, laps []Lap, rc []RaceControl) int {
+	for _, l := range laps {
+		if l.LapNumber > totalLaps {
+			totalLaps = l.LapNumber
+		}
+	}
+	for _, msg := range rc {
+		if msg.LapNumber != nil && *msg.LapNumber > totalLaps {
+			totalLaps = *msg.LapNumber
+		}
+	}
+	return totalLaps
+}
+
+type lapIndex struct {
+	byLap  map[int]string
+	events []lapEvent
+}
+
+type lapEvent struct {
+	lap int
+	at  time.Time
+}
+
+func buildLapIndex(laps []Lap) lapIndex {
+	idx := lapIndex{byLap: map[int]string{}}
+	for _, l := range laps {
+		if l.LapNumber <= 0 || l.DateStart == "" {
+			continue
+		}
+		if _, ok := idx.byLap[l.LapNumber]; !ok {
+			idx.byLap[l.LapNumber] = l.DateStart
+		}
+		at, ok := parseTime(l.DateStart)
+		if ok {
+			idx.events = append(idx.events, lapEvent{lap: l.LapNumber, at: at})
+		}
+	}
+	sort.Slice(idx.events, func(i, j int) bool {
+		if idx.events[i].at.Equal(idx.events[j].at) {
+			return idx.events[i].lap < idx.events[j].lap
+		}
+		return idx.events[i].at.Before(idx.events[j].at)
+	})
+	return idx
+}
+
+func (idx lapIndex) lapStart(lap int) string {
+	return idx.byLap[lap]
+}
+
+func (idx lapIndex) lapEnd(lap int) string {
+	if v := idx.byLap[lap+1]; v != "" {
+		return v
+	}
+	return idx.byLap[lap]
+}
+
+func (idx lapIndex) lapForTime(raw string) int {
+	at, ok := parseTime(raw)
+	if !ok || len(idx.events) == 0 {
+		return 0
+	}
+	lap := 0
+	for _, event := range idx.events {
+		if event.at.After(at) {
+			break
+		}
+		lap = event.lap
+	}
+	if lap == 0 {
+		return idx.events[0].lap
+	}
+	return lap
+}
+
+type flagState struct {
+	startLap  int
+	startTime string
+}
+
+func detectFlagPeriods(rc []RaceControl, idx lapIndex, totalLaps int) []Chapter {
+	var chapters []Chapter
+	active := map[string]flagState{}
+	for _, msg := range rc {
+		kind, ok := flagKind(msg)
+		if !ok && greenFlagClear(msg) {
+			for activeKind, st := range active {
+				lap := messageLap(msg, idx)
+				if lap <= 0 {
+					lap = st.startLap
+				}
+				endLap := clampLap(lap, st.startLap, totalLaps)
+				chapters = append(chapters, Chapter{
+					Kind:      activeKind,
+					Title:     flagTitle(activeKind, st.startLap, endLap),
+					StartLap:  st.startLap,
+					EndLap:    endLap,
+					StartTime: st.startTime,
+					EndTime:   firstNonEmpty(msg.Date, idx.lapEnd(endLap)),
+				})
+				delete(active, activeKind)
+			}
+			continue
+		}
+		if !ok {
+			continue
+		}
+		lap := messageLap(msg, idx)
+		if lap <= 0 {
+			lap = 1
+		}
+		if flagCleared(msg) {
+			st, ok := active[kind]
+			if !ok {
+				continue
+			}
+			endLap := clampLap(lap, st.startLap, totalLaps)
+			chapters = append(chapters, Chapter{
+				Kind:      kind,
+				Title:     flagTitle(kind, st.startLap, endLap),
+				StartLap:  st.startLap,
+				EndLap:    endLap,
+				StartTime: st.startTime,
+				EndTime:   firstNonEmpty(msg.Date, idx.lapEnd(endLap)),
+			})
+			delete(active, kind)
+			continue
+		}
+		if flagStarted(msg) {
+			active[kind] = flagState{
+				startLap:  clampLap(lap, 1, totalLaps),
+				startTime: firstNonEmpty(msg.Date, idx.lapStart(lap)),
+			}
+		}
+	}
+	for kind, st := range active {
+		endLap := totalLaps
+		chapters = append(chapters, Chapter{
+			Kind:      kind,
+			Title:     flagTitle(kind, st.startLap, endLap),
+			StartLap:  st.startLap,
+			EndLap:    endLap,
+			StartTime: st.startTime,
+			EndTime:   idx.lapEnd(endLap),
+		})
+	}
+	return chapters
+}
+
+func flagKind(msg RaceControl) (string, bool) {
+	text := upperText(string(msg.Category), string(msg.Flag), msg.Message)
+	if strings.Contains(text, "VSC") || strings.Contains(text, "VIRTUAL SAFETY CAR") {
+		return KindVirtualSafetyCar, true
+	}
+	if strings.Contains(text, "RED FLAG") || string(msg.Flag) == string(models.FlagRed) {
+		return KindRedFlag, true
+	}
+	if strings.Contains(text, "SAFETY CAR") || msg.Category == models.CategorySafetyCar {
+		return KindSafetyCar, true
+	}
+	return "", false
+}
+
+func flagStarted(msg RaceControl) bool {
+	text := upperText(string(msg.Category), string(msg.Flag), msg.Message)
+	if strings.Contains(text, "CLEAR") || strings.Contains(text, "ENDING") || strings.Contains(text, "IN THIS LAP") || strings.Contains(text, "GREEN") {
+		return false
+	}
+	return strings.Contains(text, "DEPLOY") ||
+		strings.Contains(text, "RED FLAG") ||
+		strings.Contains(text, "VIRTUAL SAFETY CAR") ||
+		strings.Contains(text, "VSC") ||
+		strings.Contains(text, "SAFETY CAR") ||
+		string(msg.Flag) == string(models.FlagRed)
+}
+
+func flagCleared(msg RaceControl) bool {
+	text := upperText(string(msg.Category), string(msg.Flag), msg.Message)
+	return strings.Contains(text, "CLEAR") ||
+		strings.Contains(text, "ENDING") ||
+		strings.Contains(text, "IN THIS LAP") ||
+		strings.Contains(text, "GREEN")
+}
+
+func greenFlagClear(msg RaceControl) bool {
+	text := upperText(string(msg.Flag), msg.Message)
+	return strings.Contains(text, "GREEN")
+}
+
+func flagTitle(kind string, startLap, endLap int) string {
+	name := "Flag period"
+	switch kind {
+	case KindSafetyCar:
+		name = "Safety Car"
+	case KindVirtualSafetyCar:
+		name = "Virtual Safety Car"
+	case KindRedFlag:
+		name = "Red Flag"
+	}
+	return fmt.Sprintf("%s (L%d-L%d)", name, startLap, endLap)
+}
+
+func detectPitPhases(laps []Lap, idx lapIndex) []Chapter {
+	type pitOut struct {
+		lap    int
+		driver int
+	}
+	var stops []pitOut
+	for _, l := range laps {
+		if l.IsPitOutLap && l.LapNumber > 0 {
+			stops = append(stops, pitOut{lap: l.LapNumber, driver: l.DriverNumber})
+		}
+	}
+	if len(stops) < minPitPhaseStops {
+		return nil
+	}
+	sort.Slice(stops, func(i, j int) bool {
+		if stops[i].lap == stops[j].lap {
+			return stops[i].driver < stops[j].driver
+		}
+		return stops[i].lap < stops[j].lap
+	})
+	needed := int(math.Ceil(float64(len(stops)) * pitPhaseShare))
+	if needed < minPitPhaseStops {
+		needed = minPitPhaseStops
+	}
+
+	var windows []Chapter
+	for i := 0; i < len(stops); i++ {
+		start := stops[i].lap
+		end := start + pitPhaseWindowLaps - 1
+		drivers := map[int]bool{}
+		count := 0
+		for _, stop := range stops {
+			if stop.lap < start || stop.lap > end {
+				continue
+			}
+			count++
+			drivers[stop.driver] = true
+		}
+		if count < needed {
+			continue
+		}
+		ch := Chapter{
+			Kind:          KindPitPhase,
+			Title:         fmt.Sprintf("Pit phase (L%d-L%d)", start, end),
+			StartLap:      start,
+			EndLap:        end,
+			StartTime:     idx.lapStart(start),
+			EndTime:       idx.lapEnd(end),
+			DriverNumbers: sortedDriverNumbers(drivers),
+		}
+		if len(windows) > 0 && ch.StartLap <= windows[len(windows)-1].EndLap+1 {
+			last := &windows[len(windows)-1]
+			if ch.EndLap > last.EndLap {
+				last.EndLap = ch.EndLap
+				last.EndTime = idx.lapEnd(last.EndLap)
+			}
+			drivers := sliceToSet(last.DriverNumbers)
+			for _, driver := range ch.DriverNumbers {
+				drivers[driver] = true
+			}
+			last.DriverNumbers = sortedDriverNumbers(drivers)
+			last.Title = fmt.Sprintf("Pit phase (L%d-L%d)", last.StartLap, last.EndLap)
+			continue
+		}
+		windows = append(windows, ch)
+	}
+	return windows
+}
+
+type swingCandidate struct {
+	chapter      Chapter
+	significance int
+}
+
+func detectDecisiveSwings(positions []PositionSample, idx lapIndex, totalLaps int) []Chapter {
+	if len(positions) == 0 || len(idx.events) == 0 || totalLaps <= decisiveAfterLap {
+		return nil
+	}
+	snapshots := buildPositionSnapshots(positions, idx, totalLaps)
+	if len(snapshots) == 0 {
+		return nil
+	}
+	final := snapshots[totalLaps]
+	if len(final) == 0 {
+		for lap := totalLaps - 1; lap >= 1; lap-- {
+			if len(snapshots[lap]) > 0 {
+				final = snapshots[lap]
+				break
+			}
+		}
+	}
+	var candidates []swingCandidate
+	seenDriver := map[int]bool{}
+	for lap := decisiveAfterLap + 1; lap <= totalLaps; lap++ {
+		prev := snapshots[lap-1]
+		curr := snapshots[lap]
+		if len(prev) == 0 || len(curr) == 0 {
+			continue
+		}
+		for driver, pos := range curr {
+			prevPos, ok := prev[driver]
+			if !ok || prevPos <= pos || pos > 5 || pos <= 0 || seenDriver[driver] {
+				continue
+			}
+			finalPos, ok := final[driver]
+			if !ok || finalPos > pos {
+				continue
+			}
+			overtaken := driverAtPosition(curr, prevPos, driver)
+			drivers := []int{driver}
+			if overtaken != 0 {
+				drivers = append(drivers, overtaken)
+			}
+			candidates = append(candidates, swingCandidate{
+				chapter: Chapter{
+					Kind:          KindDecisiveSwing,
+					Title:         fmt.Sprintf("Decisive swing: #%d to P%d (L%d)", driver, pos, lap),
+					StartLap:      lap,
+					EndLap:        lap,
+					StartTime:     idx.lapStart(lap),
+					EndTime:       idx.lapEnd(lap),
+					DriverNumbers: drivers,
+				},
+				significance: (prevPos-pos)*10 + (6 - pos),
+			})
+			seenDriver[driver] = true
+		}
+	}
+	sort.Slice(candidates, func(i, j int) bool {
+		if candidates[i].significance == candidates[j].significance {
+			return candidates[i].chapter.StartLap < candidates[j].chapter.StartLap
+		}
+		return candidates[i].significance > candidates[j].significance
+	})
+	if len(candidates) > maxDecisiveSwings {
+		candidates = candidates[:maxDecisiveSwings]
+	}
+	out := make([]Chapter, 0, len(candidates))
+	for _, c := range candidates {
+		out = append(out, c.chapter)
+	}
+	return out
+}
+
+func buildPositionSnapshots(positions []PositionSample, idx lapIndex, totalLaps int) map[int]map[int]int {
+	byLap := map[int][]PositionSample{}
+	for _, p := range positions {
+		if p.Position <= 0 {
+			continue
+		}
+		lap := idx.lapForTime(p.Date)
+		if lap <= 0 || lap > totalLaps {
+			continue
+		}
+		byLap[lap] = append(byLap[lap], p)
+	}
+	last := map[int]int{}
+	snapshots := map[int]map[int]int{}
+	for lap := 1; lap <= totalLaps; lap++ {
+		for _, p := range byLap[lap] {
+			last[p.DriverNumber] = p.Position
+		}
+		if len(last) == 0 {
+			continue
+		}
+		cp := make(map[int]int, len(last))
+		for driver, pos := range last {
+			cp[driver] = pos
+		}
+		snapshots[lap] = cp
+	}
+	return snapshots
+}
+
+func driverAtPosition(snapshot map[int]int, pos int, exclude int) int {
+	for driver, driverPos := range snapshot {
+		if driver != exclude && driverPos == pos {
+			return driver
+		}
+	}
+	return 0
+}
+
+func detectFinish(rc []RaceControl, idx lapIndex, totalLaps int) Chapter {
+	finishLap := totalLaps
+	finishTime := idx.lapEnd(totalLaps)
+	for _, msg := range rc {
+		text := upperText(string(msg.Flag), msg.Message)
+		if strings.Contains(text, "CHEQUER") || string(msg.Flag) == string(models.FlagChequered) {
+			if lap := messageLap(msg, idx); lap > 0 {
+				finishLap = lap
+			}
+			finishTime = firstNonEmpty(msg.Date, finishTime)
+		}
+	}
+	startLap := finishLap - 1
+	if startLap < 1 {
+		startLap = 1
+	}
+	return Chapter{
+		Kind:      KindFinish,
+		Title:     fmt.Sprintf("Finish (L%d-L%d)", startLap, finishLap),
+		StartLap:  startLap,
+		EndLap:    finishLap,
+		StartTime: idx.lapStart(startLap),
+		EndTime:   finishTime,
+	}
+}
+
+func resolveConflicts(chapters []Chapter) []Chapter {
+	normalized := make([]Chapter, 0, len(chapters))
+	for _, ch := range chapters {
+		if ch.StartLap <= 0 {
+			ch.StartLap = 1
+		}
+		if ch.EndLap <= 0 {
+			ch.EndLap = ch.StartLap
+		}
+		if ch.EndLap < ch.StartLap {
+			ch.EndLap = ch.StartLap
+		}
+		if ch.DriverNumbers == nil {
+			ch.DriverNumbers = []int{}
+		}
+		normalized = append(normalized, ch)
+	}
+	sort.SliceStable(normalized, func(i, j int) bool {
+		if normalized[i].StartLap == normalized[j].StartLap {
+			return priority(normalized[i].Kind) > priority(normalized[j].Kind)
+		}
+		return normalized[i].StartLap < normalized[j].StartLap
+	})
+
+	out := make([]Chapter, 0, len(normalized))
+	for _, ch := range normalized {
+		if len(out) == 0 {
+			out = append(out, ch)
+			continue
+		}
+		last := &out[len(out)-1]
+		if ch.StartLap > last.EndLap {
+			out = append(out, ch)
+			continue
+		}
+		if isFlag(last.Kind) && priority(ch.Kind) < priority(last.Kind) {
+			continue
+		}
+		if priority(ch.Kind) > priority(last.Kind) {
+			if last.StartLap < ch.StartLap {
+				last.EndLap = ch.StartLap - 1
+				out = append(out, ch)
+			} else {
+				*last = ch
+			}
+			continue
+		}
+		if ch.EndLap > last.EndLap {
+			ch.StartLap = last.EndLap + 1
+			if ch.StartLap <= ch.EndLap {
+				out = append(out, ch)
+			}
+		}
+	}
+	return out
+}
+
+func isFlag(kind string) bool {
+	return kind == KindSafetyCar || kind == KindVirtualSafetyCar || kind == KindRedFlag
+}
+
+func priority(kind string) int {
+	switch kind {
+	case KindStart, KindFinish:
+		return structuralPriority
+	case KindSafetyCar, KindVirtualSafetyCar, KindRedFlag:
+		return flagPriority
+	case KindPitPhase:
+		return pitPhasePriority
+	case KindDecisiveSwing:
+		return decisivePriority
+	default:
+		return 0
+	}
+}
+
+func messageLap(msg RaceControl, idx lapIndex) int {
+	if msg.LapNumber != nil && *msg.LapNumber > 0 {
+		return *msg.LapNumber
+	}
+	return idx.lapForTime(msg.Date)
+}
+
+func clampLap(lap, minLap, maxLap int) int {
+	if lap < minLap {
+		return minLap
+	}
+	if maxLap > 0 && lap > maxLap {
+		return maxLap
+	}
+	return lap
+}
+
+func parseTime(raw string) (time.Time, bool) {
+	if raw == "" {
+		return time.Time{}, false
+	}
+	at, err := time.Parse(time.RFC3339, raw)
+	if err != nil {
+		return time.Time{}, false
+	}
+	return at, true
+}
+
+func upperText(parts ...string) string {
+	return strings.ToUpper(strings.Join(parts, " "))
+}
+
+func firstNonEmpty(values ...string) string {
+	for _, value := range values {
+		if value != "" {
+			return value
+		}
+	}
+	return ""
+}
+
+func sortedDriverNumbers(drivers map[int]bool) []int {
+	out := make([]int, 0, len(drivers))
+	for driver := range drivers {
+		out = append(out, driver)
+	}
+	sort.Ints(out)
+	return out
+}
+
+func sliceToSet(values []int) map[int]bool {
+	out := make(map[int]bool, len(values))
+	for _, value := range values {
+		out[value] = true
+	}
+	return out
+}
+
+func minInt(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

internal/chapters/chapters_test.go

@@ -0,0 +1,218 @@
+package chapters
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/AmanTahiliani/box-box/internal/models"
+)
+
+func TestDetectStructuralChapters(t *testing.T) {
+	chapters := Detect(nil, nil, testLaps(10, nil), 10)
+
+	if len(chapters) < 2 {
+		t.Fatalf("chapters len = %d, want at least start and finish", len(chapters))
+	}
+	if got := chapters[0]; got.Kind != KindStart || got.StartLap != 1 || got.EndLap != 1 {
+		t.Fatalf("start chapter = %+v, want L1-L1", got)
+	}
+	got := chapters[len(chapters)-1]
+	if got.Kind != KindFinish || got.StartLap != 9 || got.EndLap != 10 {
+		t.Fatalf("finish chapter = %+v, want L9-L10", got)
+	}
+}
+
+func TestDetectReturnsEmptyWithoutData(t *testing.T) {
+	if chapters := Detect(nil, nil, nil, 0); len(chapters) != 0 {
+		t.Fatalf("chapters = %+v, want empty", chapters)
+	}
+}
+
+func TestDetectFlagPeriods(t *testing.T) {
+	tests := []struct {
+		name      string
+		start     RaceControl
+		end       RaceControl
+		wantKind  string
+		wantTitle string
+	}{
+		{
+			name:      "safety car",
+			start:     rc(12, models.CategorySafetyCar, "", "SAFETY CAR DEPLOYED"),
+			end:       rc(15, models.CategorySafetyCar, "", "SAFETY CAR IN THIS LAP"),
+			wantKind:  KindSafetyCar,
+			wantTitle: "Safety Car (L12-L15)",
+		},
+		{
+			name:      "virtual safety car",
+			start:     rc(22, models.CategoryOther, "", "VSC DEPLOYED"),
+			end:       rc(24, models.CategoryOther, "", "VSC ENDING"),
+			wantKind:  KindVirtualSafetyCar,
+			wantTitle: "Virtual Safety Car (L22-L24)",
+		},
+		{
+			name:      "red flag",
+			start:     rc(31, models.CategoryFlag, models.FlagRed, "RED FLAG"),
+			end:       rc(33, models.CategoryFlag, models.FlagGreen, "GREEN FLAG"),
+			wantKind:  KindRedFlag,
+			wantTitle: "Red Flag (L31-L33)",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			chapters := Detect([]RaceControl{tt.start, tt.end}, nil, testLaps(40, nil), 40)
+			got := findKind(chapters, tt.wantKind)
+			if got == nil {
+				t.Fatalf("chapters = %+v, want %s", chapters, tt.wantKind)
+			}
+			if got.StartLap != rcLap(tt.start) || got.EndLap != rcLap(tt.end) || got.Title != tt.wantTitle {
+				t.Fatalf("flag chapter = %+v, want %s", *got, tt.wantTitle)
+			}
+		})
+	}
+}
+
+func TestDetectPitPhaseFromPitOutLapCluster(t *testing.T) {
+	pitOuts := map[int][]int{
+		5:  {1},
+		10: {2},
+		20: {3},
+		21: {4},
+		22: {5},
+		30: {6},
+		35: {7},
+		40: {8},
+		45: {9},
+		50: {10},
+	}
+	chapters := Detect(nil, nil, testLaps(55, pitOuts), 55)
+
+	got := findKind(chapters, KindPitPhase)
+	if got == nil {
+		t.Fatalf("chapters = %+v, want pit phase", chapters)
+	}
+	if got.StartLap != 20 || got.EndLap != 22 {
+		t.Fatalf("pit phase = %+v, want L20-L22", *got)
+	}
+	if len(got.DriverNumbers) != 3 || got.DriverNumbers[0] != 3 || got.DriverNumbers[2] != 5 {
+		t.Fatalf("pit phase drivers = %v, want [3 4 5]", got.DriverNumbers)
+	}
+}
+
+func TestDetectDecisiveSwingPersistsToFinish(t *testing.T) {
+	positions := []PositionSample{
+		pos(1, 1, 1),
+		pos(1, 16, 4),
+		pos(1, 55, 3),
+		pos(6, 16, 3),
+		pos(6, 55, 4),
+		pos(8, 44, 5),
+		pos(8, 63, 6),
+		pos(10, 44, 6),
+	}
+
+	chapters := Detect(nil, positions, testLaps(12, nil), 12)
+	got := findKind(chapters, KindDecisiveSwing)
+	if got == nil {
+		t.Fatalf("chapters = %+v, want decisive swing", chapters)
+	}
+	if got.StartLap != 6 || got.EndLap != 6 {
+		t.Fatalf("swing lap = %+v, want L6", *got)
+	}
+	if len(got.DriverNumbers) != 2 || got.DriverNumbers[0] != 16 || got.DriverNumbers[1] != 55 {
+		t.Fatalf("swing drivers = %v, want [16 55]", got.DriverNumbers)
+	}
+}
+
+func TestDetectFlagPeriodsWinOverConflictingChapters(t *testing.T) {
+	pitOuts := map[int][]int{
+		12: {1, 2},
+		13: {3, 4},
+		14: {5, 6},
+	}
+	rcs := []RaceControl{
+		rc(12, models.CategorySafetyCar, "", "SAFETY CAR DEPLOYED"),
+		rc(15, models.CategorySafetyCar, "", "SAFETY CAR IN THIS LAP"),
+	}
+
+	chapters := Detect(rcs, nil, testLaps(20, pitOuts), 20)
+	if got := findKind(chapters, KindSafetyCar); got == nil || got.StartLap != 12 || got.EndLap != 15 {
+		t.Fatalf("chapters = %+v, want safety car L12-L15", chapters)
+	}
+	if got := findKind(chapters, KindPitPhase); got != nil {
+		t.Fatalf("pit phase = %+v, want omitted under safety car", *got)
+	}
+	for i := 1; i < len(chapters); i++ {
+		if chapters[i].StartLap <= chapters[i-1].EndLap {
+			t.Fatalf("chapters overlap at %d: %+v then %+v", i, chapters[i-1], chapters[i])
+		}
+	}
+}
+
+func rcLap(r RaceControl) int {
+	if r.LapNumber == nil {
+		return 0
+	}
+	return *r.LapNumber
+}
+
+func findKind(chapters []Chapter, kind string) *Chapter {
+	for i := range chapters {
+		if chapters[i].Kind == kind {
+			return &chapters[i]
+		}
+	}
+	return nil
+}
+
+func testLaps(total int, pitOuts map[int][]int) []Lap {
+	var laps []Lap
+	for lap := 1; lap <= total; lap++ {
+		drivers := []int{1}
+		if pitDrivers := pitOuts[lap]; len(pitDrivers) > 0 {
+			drivers = pitDrivers
+		}
+		for _, driver := range drivers {
+			laps = append(laps, Lap{
+				DriverNumber: driver,
+				LapNumber:    lap,
+				DateStart:    lapTime(lap),
+				IsPitOutLap:  containsDriver(pitOuts[lap], driver),
+			})
+		}
+	}
+	return laps
+}
+
+func rc(lap int, category models.RaceControlCategory, flag models.Flag, message string) RaceControl {
+	return RaceControl{
+		Category:  category,
+		Flag:      flag,
+		Message:   message,
+		LapNumber: &lap,
+		Date:      lapTime(lap),
+	}
+}
+
+func pos(lap int, driver int, position int) PositionSample {
+	return PositionSample{
+		DriverNumber: driver,
+		Position:     position,
+		Date:         lapTime(lap),
+	}
+}
+
+func lapTime(lap int) string {
+	minute := lap - 1
+	return fmt.Sprintf("2025-05-25T13:%02d:00Z", minute)
+}
+
+func containsDriver(drivers []int, driver int) bool {
+	for _, candidate := range drivers {
+		if candidate == driver {
+			return true
+		}
+	}
+	return false
+}

internal/chapters/headlines.go

@@ -0,0 +1,233 @@
+package chapters
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/AmanTahiliani/box-box/internal/models"
+)
+
+// DriverIdentityInput carries session driver fields used for headline templates.
+type DriverIdentityInput struct {
+	DriverNumber int
+	NameAcronym  string
+	FullName     string
+	TeamName     string
+}
+
+type driverIdentity struct {
+	display string
+	team    string
+	acronym string
+}
+
+// BuildDriverMap indexes driver identity from session drivers and enriched results.
+func BuildDriverMap(drivers []models.Driver, results []DriverIdentityInput) map[int]driverIdentity {
+	out := map[int]driverIdentity{}
+	for _, d := range drivers {
+		if d.DriverNumber <= 0 {
+			continue
+		}
+		out[d.DriverNumber] = driverIdentity{
+			display: driverDisplayName(d.LastName, d.FullName, d.NameAcronym, d.BroadcastName),
+			team:    d.TeamName,
+			acronym: firstNonEmpty(d.NameAcronym, d.BroadcastName),
+		}
+	}
+	for _, r := range results {
+		if r.DriverNumber <= 0 {
+			continue
+		}
+		if _, ok := out[r.DriverNumber]; ok {
+			continue
+		}
+		out[r.DriverNumber] = driverIdentity{
+			display: driverDisplayName("", r.FullName, r.NameAcronym, ""),
+			team:    r.TeamName,
+			acronym: r.NameAcronym,
+		}
+	}
+	return out
+}
+
+// ApplyHeadlines fills Headline on each chapter using deterministic templates.
+func ApplyHeadlines(chapters []Chapter, drivers map[int]driverIdentity, rc []RaceControl, winnerNumber int) []Chapter {
+	out := make([]Chapter, len(chapters))
+	copy(out, chapters)
+	for i := range out {
+		out[i].Headline = headlineFor(out[i], drivers, rc, winnerNumber)
+	}
+	return out
+}
+
+func headlineFor(ch Chapter, drivers map[int]driverIdentity, rc []RaceControl, winnerNumber int) string {
+	switch ch.Kind {
+	case KindStart:
+		return pickVariant(ch.StartLap,
+			"Lights out — the field charges into Turn 1",
+			"Race start — Lap 1 shuffle at the front",
+		)
+	case KindSafetyCar:
+		if name := driverName(ch, drivers, incidentDriver(rc, ch.StartLap)); name != "" {
+			return pickVariant(ch.StartLap,
+				fmt.Sprintf("%s incident brings out the Safety Car — leaders dive for the pits", name),
+				fmt.Sprintf("Safety Car deployed after %s stops on track", name),
+			)
+		}
+	case KindVirtualSafetyCar:
+		if name := driverName(ch, drivers, incidentDriver(rc, ch.StartLap)); name != "" {
+			return pickVariant(ch.StartLap,
+				fmt.Sprintf("%s off track triggers the Virtual Safety Car", name),
+				fmt.Sprintf("Virtual Safety Car — %s loses control on Lap %d", name, ch.StartLap),
+			)
+		}
+		return pickVariant(ch.StartLap,
+			fmt.Sprintf("Virtual Safety Car deployed on Lap %d", ch.StartLap),
+			fmt.Sprintf("VSC period — field backs off on L%d–L%d", ch.StartLap, ch.EndLap),
+		)
+	case KindRedFlag:
+		if name := driverName(ch, drivers, incidentDriver(rc, ch.StartLap)); name != "" {
+			return pickVariant(ch.StartLap,
+				fmt.Sprintf("%s crash forces a red flag on Lap %d", name, ch.StartLap),
+				fmt.Sprintf("Red flag after %s incident on Lap %d", name, ch.StartLap),
+			)
+		}
+		return pickVariant(ch.StartLap,
+			fmt.Sprintf("Red flag — session halted on Lap %d", ch.StartLap),
+			fmt.Sprintf("Race suspended under red flag on L%d–L%d", ch.StartLap, ch.EndLap),
+		)
+	case KindPitPhase:
+		names := driverNames(ch.DriverNumbers, drivers, 3)
+		if len(names) >= 2 {
+			return pickVariant(ch.StartLap,
+				fmt.Sprintf("Mass pit-window scramble — %s and %s box on L%d–L%d", names[0], names[1], ch.StartLap, ch.EndLap),
+				fmt.Sprintf("Undercut window opens — %s leads the pit rush on L%d–L%d", names[0], ch.StartLap, ch.EndLap),
+			)
+		}
+		if len(names) == 1 {
+			return pickVariant(ch.StartLap,
+				fmt.Sprintf("%s pits under green — strategy window opens on L%d", names[0], ch.StartLap),
+				fmt.Sprintf("Pit phase on L%d–L%d — %s among the first to stop", ch.StartLap, ch.EndLap, names[0]),
+			)
+		}
+	case KindDecisiveSwing:
+		if len(ch.DriverNumbers) >= 2 {
+			attacker := driverName(ch, drivers, ch.DriverNumbers[0])
+			defender := driverName(ch, drivers, ch.DriverNumbers[1])
+			pos := swingPosition(ch.Title)
+			if attacker != "" && defender != "" && pos > 0 {
+				return pickVariant(ch.StartLap,
+					fmt.Sprintf("%s overtakes %s for P%d", attacker, defender, pos),
+					fmt.Sprintf("%s charges past %s into P%d on Lap %d", attacker, defender, pos, ch.StartLap),
+				)
+			}
+		}
+		if len(ch.DriverNumbers) >= 1 {
+			attacker := driverName(ch, drivers, ch.DriverNumbers[0])
+			pos := swingPosition(ch.Title)
+			if attacker != "" && pos > 0 {
+				return pickVariant(ch.StartLap,
+					fmt.Sprintf("%s moves up to P%d on Lap %d", attacker, pos, ch.StartLap),
+					fmt.Sprintf("Decisive swing — %s climbs to P%d", attacker, pos),
+				)
+			}
+		}
+	case KindFinish:
+		winner := driverName(ch, drivers, winnerNumber)
+		if winner != "" {
+			return pickVariant(ch.StartLap,
+				fmt.Sprintf("%s crosses the line to take the win", winner),
+				fmt.Sprintf("Chequered flag — %s wins the race", winner),
+			)
+		}
+	}
+	return ch.Title
+}
+
+func pickVariant(seed int, variants ...string) string {
+	if len(variants) == 0 {
+		return ""
+	}
+	if seed < 0 {
+		seed = -seed
+	}
+	return variants[seed%len(variants)]
+}
+
+func driverName(_ Chapter, drivers map[int]driverIdentity, number int) string {
+	if number <= 0 {
+		return ""
+	}
+	if id, ok := drivers[number]; ok && id.display != "" {
+		return id.display
+	}
+	return ""
+}
+
+func driverNames(numbers []int, drivers map[int]driverIdentity, limit int) []string {
+	out := make([]string, 0, limit)
+	for _, number := range numbers {
+		if name := driverName(Chapter{}, drivers, number); name != "" {
+			out = append(out, name)
+			if len(out) >= limit {
+				break
+			}
+		}
+	}
+	return out
+}
+
+func driverDisplayName(lastName, fullName, acronym, broadcast string) string {
+	if lastName != "" {
+		return lastName
+	}
+	if fullName != "" {
+		parts := strings.Fields(fullName)
+		if len(parts) > 0 {
+			return parts[len(parts)-1]
+		}
+		return fullName
+	}
+	return firstNonEmpty(acronym, broadcast)
+}
+
+func incidentDriver(rc []RaceControl, startLap int) int {
+	for _, msg := range rc {
+		if msg.DriverNumber == nil || *msg.DriverNumber <= 0 {
+			continue
+		}
+		lap := 0
+		if msg.LapNumber != nil {
+			lap = *msg.LapNumber
+		}
+		if lap < startLap-1 || lap > startLap+1 {
+			continue
+		}
+		text := upperText(msg.Message, string(msg.Category))
+		if strings.Contains(text, "DEPLOY") ||
+			strings.Contains(text, "CLEAR") ||
+			strings.Contains(text, "ENDING") ||
+			strings.Contains(text, "GREEN") ||
+			strings.Contains(text, "CHEQUER") {
+			continue
+		}
+		return *msg.DriverNumber
+	}
+	return 0
+}
+
+func swingPosition(title string) int {
+	// Title format: "Decisive swing: #16 to P3 (L6)"
+	idx := strings.Index(title, "P")
+	if idx < 0 || idx+1 >= len(title) {
+		return 0
+	}
+	pos := 0
+	for i := idx + 1; i < len(title); i++ {
+		if title[i] < '0' || title[i] > '9' {
+			break
+		}
+		pos = pos*10 + int(title[i]-'0')
+	}
+	return pos
+}

internal/chapters/headlines_test.go

@@ -0,0 +1,199 @@
+package chapters
+
+import (
+	"testing"
+
+	"github.com/AmanTahiliani/box-box/internal/models"
+)
+
+func TestHeadlineStart(t *testing.T) {
+	ch := Chapter{Kind: KindStart, Title: "Start", StartLap: 1, EndLap: 1}
+	got := headlineFor(ch, nil, nil, 0)
+	want := "Race start — Lap 1 shuffle at the front"
+	if got != want {
+		t.Fatalf("headline = %q, want %q", got, want)
+	}
+}
+
+func TestHeadlineStartVariantByLap(t *testing.T) {
+	ch := Chapter{Kind: KindStart, Title: "Start", StartLap: 2, EndLap: 2}
+	got := headlineFor(ch, nil, nil, 0)
+	want := "Lights out — the field charges into Turn 1"
+	if got != want {
+		t.Fatalf("headline = %q, want %q", got, want)
+	}
+}
+
+func TestHeadlineSafetyCarWithDriver(t *testing.T) {
+	drivers := BuildDriverMap(nil, []DriverIdentityInput{
+		{DriverNumber: 55, NameAcronym: "SAI", FullName: "Carlos Sainz", TeamName: "Ferrari"},
+	})
+	rc := []RaceControl{
+		{
+			DriverNumber: intPtr(55),
+			LapNumber:    intPtr(12),
+			Message:      "CAR 55 STOPPED ON TRACK",
+		},
+		rc(12, models.CategorySafetyCar, "", "SAFETY CAR DEPLOYED"),
+		rc(15, models.CategorySafetyCar, "", "SAFETY CAR IN THIS LAP"),
+	}
+	ch := Chapter{
+		Kind:     KindSafetyCar,
+		Title:    "Safety Car (L12-L15)",
+		StartLap: 12,
+		EndLap:   15,
+	}
+	got := headlineFor(ch, drivers, rc, 0)
+	want := "Sainz incident brings out the Safety Car — leaders dive for the pits"
+	if got != want {
+		t.Fatalf("headline = %q, want %q", got, want)
+	}
+}
+
+func TestHeadlineSafetyCarFallbackWithoutDriver(t *testing.T) {
+	ch := Chapter{
+		Kind:     KindSafetyCar,
+		Title:    "Safety Car (L12-L15)",
+		StartLap: 12,
+		EndLap:   15,
+	}
+	got := headlineFor(ch, nil, nil, 0)
+	if got != ch.Title {
+		t.Fatalf("headline = %q, want fallback %q", got, ch.Title)
+	}
+}
+
+func TestHeadlineVirtualSafetyCar(t *testing.T) {
+	drivers := BuildDriverMap(nil, []DriverIdentityInput{
+		{DriverNumber: 16, NameAcronym: "LEC", FullName: "Charles Leclerc", TeamName: "Ferrari"},
+	})
+	rc := []RaceControl{
+		{
+			DriverNumber: intPtr(16),
+			LapNumber:    intPtr(22),
+			Message:      "CAR 16 OFF TRACK",
+		},
+		rc(22, models.CategoryOther, "", "VSC DEPLOYED"),
+		rc(24, models.CategoryOther, "", "VSC ENDING"),
+	}
+	ch := Chapter{
+		Kind:     KindVirtualSafetyCar,
+		Title:    "Virtual Safety Car (L22-L24)",
+		StartLap: 22,
+		EndLap:   24,
+	}
+	got := headlineFor(ch, drivers, rc, 0)
+	want := "Leclerc off track triggers the Virtual Safety Car"
+	if got != want {
+		t.Fatalf("headline = %q, want %q", got, want)
+	}
+}
+
+func TestHeadlineRedFlag(t *testing.T) {
+	drivers := BuildDriverMap(nil, []DriverIdentityInput{
+		{DriverNumber: 63, NameAcronym: "RUS", FullName: "George Russell", TeamName: "Mercedes"},
+	})
+	rc := []RaceControl{
+		{
+			DriverNumber: intPtr(63),
+			LapNumber:    intPtr(31),
+			Message:      "INCIDENT INVOLVING CAR 63",
+		},
+		rc(31, models.CategoryFlag, models.FlagRed, "RED FLAG"),
+		rc(33, models.CategoryFlag, models.FlagGreen, "GREEN FLAG"),
+	}
+	ch := Chapter{
+		Kind:     KindRedFlag,
+		Title:    "Red Flag (L31-L33)",
+		StartLap: 31,
+		EndLap:   33,
+	}
+	got := headlineFor(ch, drivers, rc, 0)
+	want := "Red flag after Russell incident on Lap 31"
+	if got != want {
+		t.Fatalf("headline = %q, want %q", got, want)
+	}
+}
+
+func TestHeadlinePitPhase(t *testing.T) {
+	drivers := BuildDriverMap(nil, []DriverIdentityInput{
+		{DriverNumber: 1, NameAcronym: "VER", FullName: "Max Verstappen", TeamName: "Red Bull"},
+		{DriverNumber: 44, NameAcronym: "HAM", FullName: "Lewis Hamilton", TeamName: "Mercedes"},
+		{DriverNumber: 16, NameAcronym: "LEC", FullName: "Charles Leclerc", TeamName: "Ferrari"},
+	})
+	ch := Chapter{
+		Kind:          KindPitPhase,
+		Title:         "Pit phase (L20-L22)",
+		StartLap:      20,
+		EndLap:        22,
+		DriverNumbers: []int{1, 44, 16},
+	}
+	got := headlineFor(ch, drivers, nil, 0)
+	want := "Mass pit-window scramble — Verstappen and Hamilton box on L20–L22"
+	if got != want {
+		t.Fatalf("headline = %q, want %q", got, want)
+	}
+}
+
+func TestHeadlineDecisiveSwing(t *testing.T) {
+	drivers := BuildDriverMap(nil, []DriverIdentityInput{
+		{DriverNumber: 16, NameAcronym: "LEC", FullName: "Charles Leclerc", TeamName: "Ferrari"},
+		{DriverNumber: 55, NameAcronym: "SAI", FullName: "Carlos Sainz", TeamName: "Ferrari"},
+	})
+	ch := Chapter{
+		Kind:          KindDecisiveSwing,
+		Title:         "Decisive swing: #16 to P3 (L6)",
+		StartLap:      6,
+		EndLap:        6,
+		DriverNumbers: []int{16, 55},
+	}
+	got := headlineFor(ch, drivers, nil, 0)
+	want := "Leclerc overtakes Sainz for P3"
+	if got != want {
+		t.Fatalf("headline = %q, want %q", got, want)
+	}
+}
+
+func TestHeadlineFinish(t *testing.T) {
+	drivers := BuildDriverMap(nil, []DriverIdentityInput{
+		{DriverNumber: 1, NameAcronym: "VER", FullName: "Max Verstappen", TeamName: "Red Bull"},
+	})
+	ch := Chapter{
+		Kind:     KindFinish,
+		Title:    "Finish (L57-L58)",
+		StartLap: 57,
+		EndLap:   58,
+	}
+	got := headlineFor(ch, drivers, nil, 1)
+	want := "Chequered flag — Verstappen wins the race"
+	if got != want {
+		t.Fatalf("headline = %q, want %q", got, want)
+	}
+}
+
+func TestHeadlineFinishFallbackWithoutWinner(t *testing.T) {
+	ch := Chapter{
+		Kind:     KindFinish,
+		Title:    "Finish (L57-L58)",
+		StartLap: 57,
+		EndLap:   58,
+	}
+	got := headlineFor(ch, nil, nil, 0)
+	if got != ch.Title {
+		t.Fatalf("headline = %q, want fallback %q", got, ch.Title)
+	}
+}
+
+func TestApplyHeadlinesPreservesChapterFields(t *testing.T) {
+	input := []Chapter{
+		{Kind: KindStart, Title: "Start", StartLap: 1, EndLap: 1},
+	}
+	got := ApplyHeadlines(input, nil, nil, 0)
+	if len(got) != 1 || got[0].StartLap != 1 || got[0].Headline == "" {
+		t.Fatalf("ApplyHeadlines = %+v, want headline on start chapter", got)
+	}
+}
+
+func intPtr(v int) *int {
+	return &v
+}

internal/query/racehub.go

@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"errors"
 
+	"github.com/AmanTahiliani/box-box/internal/chapters"
 	"github.com/AmanTahiliani/box-box/internal/models"
 	"github.com/AmanTahiliani/box-box/internal/store"
 )
@@ -52,6 +53,7 @@ type RaceHub struct {
 	RaceControl  []models.RaceControl   `json:"race_control"`
 	Weather      []models.Weather       `json:"weather"`
 	Laps         []models.Lap           `json:"laps"`
+	Chapters     []chapters.Chapter     `json:"chapters"`
 }
 
 // GetRaceHub loads ingested Race Hub datasets for a session from the local store.
@@ -80,6 +82,7 @@ func (s *Service) GetRaceHub(sessionKey int) (RaceHub, error) {
 		RaceControl:  []models.RaceControl{},
 		Weather:      []models.Weather{},
 		Laps:         []models.Lap{},
+		Chapters:     []chapters.Chapter{},
 	}
 
 	sess, err := s.store.GetSession(sessionKey)
@@ -248,6 +251,50 @@ func (s *Service) GetRaceHub(sessionKey int) (RaceHub, error) {
 		hub.Datasets["laps"] = availableLocal(len(hub.Laps))
 	}
 
+	hub.Chapters = chapters.Detect(hub.RaceControl, hub.Positions, hub.Laps, totalLaps(hub.Results, hub.Laps))
+	hub.Chapters = chapters.ApplyHeadlines(
+		hub.Chapters,
+		chapters.BuildDriverMap(hub.Drivers, driverIdentityInputs(hub.Results)),
+		hub.RaceControl,
+		winnerDriverNumber(hub.Results),
+	)
 	hub.Source = responseSource(hub.Datasets)
 	return hub, nil
 }
+
+func driverIdentityInputs(results []EnrichedResult) []chapters.DriverIdentityInput {
+	out := make([]chapters.DriverIdentityInput, 0, len(results))
+	for _, r := range results {
+		out = append(out, chapters.DriverIdentityInput{
+			DriverNumber: r.DriverNumber,
+			NameAcronym:  r.NameAcronym,
+			FullName:     r.FullName,
+			TeamName:     r.TeamName,
+		})
+	}
+	return out
+}
+
+func winnerDriverNumber(results []EnrichedResult) int {
+	for _, r := range results {
+		if r.Position == 1 {
+			return r.DriverNumber
+		}
+	}
+	return 0
+}
+
+func totalLaps(results []EnrichedResult, laps []models.Lap) int {
+	total := 0
+	for _, result := range results {
+		if result.NumberOfLaps > total {
+			total = result.NumberOfLaps
+		}
+	}
+	for _, lap := range laps {
+		if lap.LapNumber > total {
+			total = lap.LapNumber
+		}
+	}
+	return total
+}

internal/web/api.go

@@ -614,8 +614,9 @@ type champHubDriver struct {
 	Wins           int       `json:"wins"`
 	Podiums        int       `json:"podiums"`
 	Poles          int       `json:"poles"`
-	Form           []float64 `json:"form"`       // last 5 races' points
-	Cumulative     []float64 `json:"cumulative"` // running total per completed round
+	Form           []float64 `json:"form"`            // last 5 races' points
+	Cumulative     []float64 `json:"cumulative"`      // running total per completed round
+	RoundPositions []int     `json:"round_positions"` // finishing position per completed round (0 = no result)
 	TeammateWins   int       `json:"teammate_wins"`
 	TeammateLosses int       `json:"teammate_losses"`
 }
@@ -797,11 +798,6 @@ func (s *Server) localChampionshipHub(year int) (champHubResponse, bool, error)
 }
 
 func (s *Server) openF1ChampionshipHub(year int) (champHubResponse, error) {
-	meetings, err := s.client.GetMeetingsForYear(year)
-	if err != nil {
-		return champHubResponse{}, err
-	}
-
 	champ, err := s.client.GetDriverChampionshipForYear(year)
 	if err != nil {
 		return champHubResponse{}, err
@@ -816,16 +812,39 @@ func (s *Server) openF1ChampionshipHub(year int) (champHubResponse, error) {
 		driverInfo = buildDriverMapFirst(ds)
 	}
 
+	races, incomplete, err := s.fetchSeasonRaces(year)
+	if err != nil {
+		return champHubResponse{}, err
+	}
+
+	resp := aggregateChampionshipHub(year, races, champ, teams, driverInfo)
+	ttl := champHubTTL(year, time.Now())
+	if incomplete {
+		// Any per-meeting fetch failure (network, rate limit) yields an incomplete
+		// aggregate: serve it so the page still renders, but cache it only briefly
+		// so a partial view of the season doesn't stick around for the full TTL.
+		ttl = champHubIncompleteTTL
+	}
+	s.hubCache.put(year, resp, time.Now(), ttl)
+	return resp, nil
+}
+
+// fetchSeasonRaces returns a season's GP meetings in date order, each bundled
+// with its race results and starting grid fetched from OpenF1. incomplete
+// reports whether any per-meeting fetch failed, so callers can avoid caching a
+// partial view of the season for long.
+func (s *Server) fetchSeasonRaces(year int) (races []meetingRace, incomplete bool, err error) {
+	meetings, err := s.client.GetMeetingsForYear(year)
+	if err != nil {
+		return nil, false, err
+	}
 	sort.Slice(meetings, func(i, j int) bool { return meetings[i].DateStart < meetings[j].DateStart })
 
-	// Any per-meeting fetch failure (network, rate limit) yields an incomplete
-	// aggregate: serve it so the page still renders, but cache it only briefly
-	// so a partial view of the season doesn't stick around for the full TTL.
-	var incomplete atomic.Bool
-	races := fetchMeetingRaces(meetings, champHubWorkers, func(m models.Meeting) (meetingRace, bool) {
+	var failed atomic.Bool
+	races = fetchMeetingRaces(meetings, champHubWorkers, func(m models.Meeting) (meetingRace, bool) {
 		sessions, serr := s.client.GetSessionsForMeeting(int(m.MeetingKey))
 		if serr != nil {
-			incomplete.Store(true)
+			failed.Store(true)
 			return meetingRace{}, false
 		}
 		raceKey := 0
@@ -841,18 +860,11 @@ func (s *Server) openF1ChampionshipHub(year int) (champHubResponse, error) {
 		results, rerr := s.client.GetSessionResult(raceKey)
 		grid, gerr := s.client.GetStartingGrid(raceKey)
 		if rerr != nil || gerr != nil {
-			incomplete.Store(true)
+			failed.Store(true)
 		}
 		return meetingRace{Meeting: m, RaceSessionKey: raceKey, Results: results, Grid: grid}, true
 	})
-
-	resp := aggregateChampionshipHub(year, races, champ, teams, driverInfo)
-	ttl := champHubTTL(year, time.Now())
-	if incomplete.Load() {
-		ttl = champHubIncompleteTTL
-	}
-	s.hubCache.put(year, resp, time.Now(), ttl)
-	return resp, nil
+	return races, failed.Load(), nil
 }
 
 // aggregateChampionshipHub is the pure aggregation core (no network) so it can be
@@ -984,6 +996,10 @@ func aggregateChampionshipHub(
 		if len(form) > 5 {
 			form = form[len(form)-5:]
 		}
+		roundPositions := make([]int, completed)
+		for round := 1; round <= completed; round++ {
+			roundPositions[round-1] = a.finishByRound[round]
+		}
 		info := driverInfo[c.DriverNumber]
 		drivers = append(drivers, champHubDriver{
 			DriverNumber:   c.DriverNumber,
@@ -998,6 +1014,7 @@ func aggregateChampionshipHub(
 			Poles:          a.poles,
 			Form:           form,
 			Cumulative:     cumulative[c.DriverNumber],
+			RoundPositions: roundPositions,
 			TeammateWins:   twins[c.DriverNumber],
 			TeammateLosses: tloss[c.DriverNumber],
 		})

internal/web/championship_hub_test.go

@@ -17,20 +17,22 @@ func TestAggregateChampionshipHub(t *testing.T) {
 		1: {DriverNumber: 1, NameAcronym: "VER", FullName: "Max Verstappen", TeamName: "Red Bull", TeamColour: "3671c6"},
 		2: {DriverNumber: 2, NameAcronym: "PER", FullName: "Sergio Perez", TeamName: "Red Bull", TeamColour: "3671c6"},
 		3: {DriverNumber: 3, NameAcronym: "HAM", FullName: "Lewis Hamilton", TeamName: "Mercedes", TeamColour: "27f4d2"},
+		4: {DriverNumber: 4, NameAcronym: "NOR", FullName: "Lando Norris", TeamName: "McLaren", TeamColour: "ff8000"},
 	}
 
 	champ := []models.ChampionshipDriver{
 		{DriverNumber: 1, PointsCurrent: 50, PositionCurrent: 1, SessionKey: 99},
 		{DriverNumber: 3, PointsCurrent: 33, PositionCurrent: 2, SessionKey: 99},
 		{DriverNumber: 2, PointsCurrent: 30, PositionCurrent: 3, SessionKey: 99},
+		{DriverNumber: 4, PointsCurrent: 12, PositionCurrent: 4, SessionKey: 99},
 	}
 	teams := []models.ChampionshipTeam{
 		{TeamName: "Red Bull", PointsCurrent: 80, PositionCurrent: 1},
 		{TeamName: "Mercedes", PointsCurrent: 33, PositionCurrent: 2},
 	}
 
-	// Round 1: VER P1(25), HAM P2(18), PER P3(15). Pole: VER.
-	// Round 2: VER P1(25), PER P2(18), HAM P3(15). Pole: HAM.
+	// Round 1: VER P1(25), HAM P2(18), PER P3(15). Pole: VER. NOR absent.
+	// Round 2: VER P1(25), PER P2(18), HAM P3(15), NOR P4(12). Pole: HAM.
 	races := []meetingRace{
 		{
 			Meeting: models.Meeting{MeetingName: "Bahrain GP"},
@@ -39,7 +41,7 @@ func TestAggregateChampionshipHub(t *testing.T) {
 		},
 		{
 			Meeting: models.Meeting{MeetingName: "Saudi GP"},
-			Results: []models.SessionResult{raceResult(1, 1, 25), raceResult(2, 2, 18), raceResult(3, 3, 15)},
+			Results: []models.SessionResult{raceResult(1, 1, 25), raceResult(2, 2, 18), raceResult(3, 3, 15), raceResult(4, 4, 12)},
 			Grid:    []models.StartingGrid{{DriverNumber: 3, Position: 1}},
 		},
 		// Round 3: not yet run (no results) — should not count as completed.
@@ -67,9 +69,9 @@ func TestAggregateChampionshipHub(t *testing.T) {
 		t.Errorf("round labels = %v, want [R1 R2]", resp.RoundLabels)
 	}
 
-	// Drivers are sorted by official position: VER, HAM, PER.
-	if len(resp.Drivers) != 3 {
-		t.Fatalf("drivers = %d, want 3", len(resp.Drivers))
+	// Drivers are sorted by official position: VER, HAM, PER, NOR.
+	if len(resp.Drivers) != 4 {
+		t.Fatalf("drivers = %d, want 4", len(resp.Drivers))
 	}
 	ver := resp.Drivers[0]
 	if ver.NameAcronym != "VER" || ver.Position != 1 {
@@ -91,6 +93,9 @@ func TestAggregateChampionshipHub(t *testing.T) {
 	if len(ver.Cumulative) != 2 || ver.Cumulative[0] != 25 || ver.Cumulative[1] != 50 {
 		t.Errorf("VER cumulative = %v, want [25 50]", ver.Cumulative)
 	}
+	if len(ver.RoundPositions) != 2 || ver.RoundPositions[0] != 1 || ver.RoundPositions[1] != 1 {
+		t.Errorf("VER round positions = %v, want [1 1]", ver.RoundPositions)
+	}
 	// VER beat teammate PER in both rounds.
 	if ver.TeammateWins != 2 || ver.TeammateLosses != 0 {
 		t.Errorf("VER h2h = %d-%d, want 2-0", ver.TeammateWins, ver.TeammateLosses)
@@ -109,6 +114,9 @@ func TestAggregateChampionshipHub(t *testing.T) {
 	if per.Poles != 0 {
 		t.Errorf("PER poles = %d, want 0", per.Poles)
 	}
+	if len(per.RoundPositions) != 2 || per.RoundPositions[0] != 3 || per.RoundPositions[1] != 2 {
+		t.Errorf("PER round positions = %v, want [3 2]", per.RoundPositions)
+	}
 
 	// HAM has no teammate in the data — no h2h recorded.
 	var ham champHubDriver
@@ -124,6 +132,17 @@ func TestAggregateChampionshipHub(t *testing.T) {
 		t.Errorf("HAM poles = %d, want 1", ham.Poles)
 	}
 
+	// NOR missed round 1 — position 0 marks the absent round.
+	var nor champHubDriver
+	for _, d := range resp.Drivers {
+		if d.NameAcronym == "NOR" {
+			nor = d
+		}
+	}
+	if len(nor.RoundPositions) != 2 || nor.RoundPositions[0] != 0 || nor.RoundPositions[1] != 4 {
+		t.Errorf("NOR round positions = %v, want [0 4]", nor.RoundPositions)
+	}
+
 	// Teams sorted by position; Red Bull wins = VER(2) + PER(0) = 2.
 	if len(resp.Teams) != 2 {
 		t.Fatalf("teams = %d, want 2", len(resp.Teams))

internal/web/driversummary.go

@@ -0,0 +1,177 @@
+package web
+
+import (
+	"fmt"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/AmanTahiliani/box-box/internal/models"
+)
+
+// --- /api/v1/driver/summary ---
+// Per-driver season summary: championship standing plus per-round race results,
+// aggregated server-side from the same sources as the championship hub. Caching
+// relies on the OpenF1 client's HTTP cache TTLs — no extra layer here.
+
+type driverSummaryRound struct {
+	MeetingKey  int    `json:"meeting_key"`
+	MeetingName string `json:"meeting_name"`
+	CountryCode string `json:"country_code"`
+	CountryName string `json:"country_name"`
+	// RacePosition and GridPosition are 0 when the driver has no entry for the
+	// round (did not enter, or data missing).
+	RacePosition int `json:"race_position"`
+	GridPosition int `json:"grid_position"`
+	// QualiPosition is derived from the starting grid in v1 (full qualifying
+	// session results are deferred); omitted when unknown.
+	QualiPosition int     `json:"quali_position,omitempty"`
+	Points        float64 `json:"points"`
+	DNF           bool    `json:"dnf"`
+	DNS           bool    `json:"dns"`
+	DSQ           bool    `json:"dsq"`
+}
+
+type driverSummaryResponse struct {
+	Season       int                  `json:"season"`
+	DriverNumber int                  `json:"driver_number"`
+	NameAcronym  string               `json:"name_acronym"`
+	FullName     string               `json:"full_name"`
+	TeamName     string               `json:"team_name"`
+	TeamColour   string               `json:"team_colour"`
+	HeadshotURL  string               `json:"headshot_url"`
+	Points       float64              `json:"points"`
+	Position     int                  `json:"position"`
+	Wins         int                  `json:"wins"`
+	Podiums      int                  `json:"podiums"`
+	Poles        int                  `json:"poles"`
+	Form         []float64            `json:"form"`
+	Cumulative   []float64            `json:"cumulative"`
+	RoundLabels  []string             `json:"round_labels"`
+	Rounds       []driverSummaryRound `json:"rounds"`
+}
+
+func (s *Server) handleDriverSummary(w http.ResponseWriter, r *http.Request) {
+	driverNumber, err := strconv.Atoi(r.URL.Query().Get("driver_number"))
+	if err != nil || driverNumber <= 0 {
+		http.Error(w, "driver_number required", http.StatusBadRequest)
+		return
+	}
+	year, _ := strconv.Atoi(r.URL.Query().Get("year"))
+	if year == 0 {
+		year = time.Now().Year()
+	}
+
+	champ, err := s.client.GetDriverChampionshipForYear(year)
+	if err != nil {
+		writeError(w, err, http.StatusInternalServerError, s.client.LastResponseWasStale())
+		return
+	}
+	var entry *models.ChampionshipDriver
+	for i := range champ {
+		if champ[i].DriverNumber == driverNumber {
+			entry = &champ[i]
+			break
+		}
+	}
+	if entry == nil {
+		http.Error(w, fmt.Sprintf("driver %d not found in %d championship", driverNumber, year), http.StatusNotFound)
+		return
+	}
+
+	driverInfo := map[int]models.Driver{}
+	if ds, derr := s.client.GetDriversForSession(champ[0].SessionKey); derr == nil {
+		driverInfo = buildDriverMapFirst(ds)
+	}
+	if d, ok := s.championshipDriverInfo(entry.SessionKey, driverNumber, driverInfo); ok {
+		driverInfo[driverNumber] = d
+	}
+
+	races, _, err := s.fetchSeasonRaces(year)
+	if err != nil {
+		writeError(w, err, http.StatusInternalServerError, s.client.LastResponseWasStale())
+		return
+	}
+
+	resp, ok := aggregateDriverSummary(year, driverNumber, races, champ, driverInfo)
+	if !ok {
+		http.Error(w, fmt.Sprintf("driver %d not found in %d championship", driverNumber, year), http.StatusNotFound)
+		return
+	}
+	writeJSON(w, resp)
+}
+
+// aggregateDriverSummary is the pure aggregation core (no network) so it can be
+// unit-tested with synthetic data. It reuses the championship-hub aggregation
+// for the derived season stats (wins, podiums, poles, form, cumulative) and
+// adds the per-round result rows. races must be ordered ascending by date and
+// contain only GP meetings. Returns ok=false when the driver is not in champ.
+func aggregateDriverSummary(
+	year, driverNumber int,
+	races []meetingRace,
+	champ []models.ChampionshipDriver,
+	driverInfo map[int]models.Driver,
+) (driverSummaryResponse, bool) {
+	hub := aggregateChampionshipHub(year, races, champ, nil, driverInfo)
+
+	var hd *champHubDriver
+	for i := range hub.Drivers {
+		if hub.Drivers[i].DriverNumber == driverNumber {
+			hd = &hub.Drivers[i]
+			break
+		}
+	}
+	if hd == nil {
+		return driverSummaryResponse{}, false
+	}
+
+	rounds := make([]driverSummaryRound, 0, len(races))
+	for _, mr := range races {
+		if len(mr.Results) == 0 {
+			continue // round not completed yet
+		}
+		round := driverSummaryRound{
+			MeetingKey:  int(mr.Meeting.MeetingKey),
+			MeetingName: mr.Meeting.MeetingName,
+			CountryCode: mr.Meeting.CountryCode,
+			CountryName: mr.Meeting.CountryName,
+		}
+		for _, res := range mr.Results {
+			if res.DriverNumber == driverNumber {
+				round.RacePosition = res.Position
+				round.Points = res.Points
+				round.DNF = res.DNF
+				round.DNS = res.DNS
+				round.DSQ = res.DSQ
+				break
+			}
+		}
+		for _, g := range mr.Grid {
+			if g.DriverNumber == driverNumber {
+				round.GridPosition = g.Position
+				round.QualiPosition = g.Position
+				break
+			}
+		}
+		rounds = append(rounds, round)
+	}
+
+	return driverSummaryResponse{
+		Season:       year,
+		DriverNumber: hd.DriverNumber,
+		NameAcronym:  hd.NameAcronym,
+		FullName:     hd.FullName,
+		TeamName:     hd.TeamName,
+		TeamColour:   hd.TeamColour,
+		HeadshotURL:  driverInfo[driverNumber].HeadshotURL,
+		Points:       hd.Points,
+		Position:     hd.Position,
+		Wins:         hd.Wins,
+		Podiums:      hd.Podiums,
+		Poles:        hd.Poles,
+		Form:         hd.Form,
+		Cumulative:   hd.Cumulative,
+		RoundLabels:  hub.RoundLabels,
+		Rounds:       rounds,
+	}, true
+}

internal/web/driversummary_test.go

@@ -0,0 +1,136 @@
+package web
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/AmanTahiliani/box-box/internal/models"
+)
+
+func driverSummaryFixtures() ([]meetingRace, []models.ChampionshipDriver, map[int]models.Driver) {
+	driverInfo := map[int]models.Driver{
+		1: {DriverNumber: 1, NameAcronym: "VER", FullName: "Max Verstappen", TeamName: "Red Bull", TeamColour: "3671c6", HeadshotURL: "https://example.com/ver.png"},
+		3: {DriverNumber: 3, NameAcronym: "HAM", FullName: "Lewis Hamilton", TeamName: "Mercedes", TeamColour: "27f4d2"},
+	}
+
+	champ := []models.ChampionshipDriver{
+		{DriverNumber: 1, PointsCurrent: 50, PositionCurrent: 1, SessionKey: 99},
+		{DriverNumber: 3, PointsCurrent: 33, PositionCurrent: 2, SessionKey: 99},
+	}
+
+	// Round 1: VER P1 from pole, HAM P2 from P3.
+	// Round 2: VER P1 from P2, HAM P3 from pole.
+	// Round 3: not yet run — must not appear in rounds.
+	races := []meetingRace{
+		{
+			Meeting: models.Meeting{MeetingKey: 1201, MeetingName: "Bahrain GP", CountryCode: "BHR", CountryName: "Bahrain"},
+			Results: []models.SessionResult{raceResult(1, 1, 25), raceResult(3, 2, 18)},
+			Grid:    []models.StartingGrid{{DriverNumber: 1, Position: 1}, {DriverNumber: 3, Position: 3}},
+		},
+		{
+			Meeting: models.Meeting{MeetingKey: 1202, MeetingName: "Saudi GP", CountryCode: "SAU", CountryName: "Saudi Arabia"},
+			Results: []models.SessionResult{raceResult(1, 1, 25), raceResult(3, 3, 15)},
+			Grid:    []models.StartingGrid{{DriverNumber: 3, Position: 1}, {DriverNumber: 1, Position: 2}},
+		},
+		{Meeting: models.Meeting{MeetingKey: 1203, MeetingName: "Australia GP"}},
+	}
+	return races, champ, driverInfo
+}
+
+func TestAggregateDriverSummary(t *testing.T) {
+	races, champ, driverInfo := driverSummaryFixtures()
+
+	resp, ok := aggregateDriverSummary(2025, 1, races, champ, driverInfo)
+	if !ok {
+		t.Fatal("aggregateDriverSummary ok = false, want true")
+	}
+
+	if resp.Season != 2025 || resp.DriverNumber != 1 {
+		t.Errorf("season/driver = %d/%d, want 2025/1", resp.Season, resp.DriverNumber)
+	}
+	if resp.NameAcronym != "VER" || resp.FullName != "Max Verstappen" || resp.TeamName != "Red Bull" || resp.TeamColour != "3671c6" {
+		t.Errorf("driver identity = %s %s %s %s", resp.NameAcronym, resp.FullName, resp.TeamName, resp.TeamColour)
+	}
+	if resp.HeadshotURL != "https://example.com/ver.png" {
+		t.Errorf("headshot = %q", resp.HeadshotURL)
+	}
+	if resp.Points != 50 || resp.Position != 1 {
+		t.Errorf("points/position = %v/%d, want 50/1", resp.Points, resp.Position)
+	}
+	if resp.Wins != 2 || resp.Podiums != 2 || resp.Poles != 1 {
+		t.Errorf("wins/podiums/poles = %d/%d/%d, want 2/2/1", resp.Wins, resp.Podiums, resp.Poles)
+	}
+	if len(resp.Form) != 2 || resp.Form[0] != 25 || resp.Form[1] != 25 {
+		t.Errorf("form = %v, want [25 25]", resp.Form)
+	}
+	// Cumulative reconciles the last value to the official total.
+	if len(resp.Cumulative) != 2 || resp.Cumulative[0] != 25 || resp.Cumulative[1] != 50 {
+		t.Errorf("cumulative = %v, want [25 50]", resp.Cumulative)
+	}
+	if len(resp.RoundLabels) != 2 || resp.RoundLabels[0] != "R1" {
+		t.Errorf("round labels = %v, want [R1 R2]", resp.RoundLabels)
+	}
+
+	// Only completed rounds appear.
+	if len(resp.Rounds) != 2 {
+		t.Fatalf("rounds = %d, want 2", len(resp.Rounds))
+	}
+	r1 := resp.Rounds[0]
+	if r1.MeetingKey != 1201 || r1.MeetingName != "Bahrain GP" || r1.CountryCode != "BHR" || r1.CountryName != "Bahrain" {
+		t.Errorf("round 1 meeting = %+v", r1)
+	}
+	if r1.RacePosition != 1 || r1.GridPosition != 1 || r1.QualiPosition != 1 || r1.Points != 25 {
+		t.Errorf("round 1 result = %+v, want P1 from P1 with 25 pts", r1)
+	}
+	r2 := resp.Rounds[1]
+	if r2.RacePosition != 1 || r2.GridPosition != 2 || r2.Points != 25 {
+		t.Errorf("round 2 result = %+v, want P1 from P2 with 25 pts", r2)
+	}
+}
+
+func TestAggregateDriverSummaryDriverMissingFromRound(t *testing.T) {
+	races, champ, driverInfo := driverSummaryFixtures()
+	// Drop HAM from round 2's results and grid: the round still appears with
+	// zero-valued positions so round indexing stays aligned with the season.
+	races[1].Results = []models.SessionResult{raceResult(1, 1, 25)}
+	races[1].Grid = []models.StartingGrid{{DriverNumber: 1, Position: 2}}
+
+	resp, ok := aggregateDriverSummary(2025, 3, races, champ, driverInfo)
+	if !ok {
+		t.Fatal("aggregateDriverSummary ok = false, want true")
+	}
+	if len(resp.Rounds) != 2 {
+		t.Fatalf("rounds = %d, want 2", len(resp.Rounds))
+	}
+	r2 := resp.Rounds[1]
+	if r2.RacePosition != 0 || r2.GridPosition != 0 || r2.QualiPosition != 0 || r2.Points != 0 {
+		t.Errorf("round 2 for absent driver = %+v, want zero values", r2)
+	}
+}
+
+func TestAggregateDriverSummaryUnknownDriver(t *testing.T) {
+	races, champ, driverInfo := driverSummaryFixtures()
+	if _, ok := aggregateDriverSummary(2025, 44, races, champ, driverInfo); ok {
+		t.Error("unknown driver should return ok = false")
+	}
+}
+
+func TestHandleDriverSummaryBadRequest(t *testing.T) {
+	srv := testServer(t, nil)
+
+	// Missing, non-numeric, zero, and negative driver_number are all rejected.
+	for _, url := range []string{
+		"/api/v1/driver/summary?year=2025",
+		"/api/v1/driver/summary?year=2025&driver_number=abc",
+		"/api/v1/driver/summary?year=2025&driver_number=0",
+		"/api/v1/driver/summary?year=2025&driver_number=-4",
+	} {
+		req := httptest.NewRequest(http.MethodGet, url, nil)
+		rec := httptest.NewRecorder()
+		srv.handleDriverSummary(rec, req)
+		if rec.Code != http.StatusBadRequest {
+			t.Errorf("%s: status = %d, want 400", url, rec.Code)
+		}
+	}
+}

internal/web/racehub.go

@@ -4,6 +4,7 @@ import (
 	"net/http"
 	"strconv"
 
+	"github.com/AmanTahiliani/box-box/internal/chapters"
 	"github.com/AmanTahiliani/box-box/internal/models"
 	"github.com/AmanTahiliani/box-box/internal/query"
 )
@@ -42,5 +43,6 @@ func emptyRaceHub(sessionKey int) query.RaceHub {
 		Drivers:      []models.Driver{},
 		Results:      []query.EnrichedResult{},
 		StartingGrid: []query.EnrichedGrid{},
+		Chapters:     []chapters.Chapter{},
 	}
 }

internal/web/racehub_test.go

@@ -119,6 +119,66 @@ func TestHandleRaceHubWithLocalData(t *testing.T) {
 	}
 }
 
+func TestHandleRaceHubIncludesChapters(t *testing.T) {
+	st := openTestStore(t)
+	seedRaceHubStore(t, st)
+	sessionKey := 9472
+	meetingKey := 1229
+
+	for lap := 1; lap <= 12; lap++ {
+		if err := st.UpsertLap(store.Lap{
+			SessionKey:   sessionKey,
+			DriverNumber: 1,
+			MeetingKey:   meetingKey,
+			LapNumber:    lap,
+			DateStart:    time.Date(2025, 5, 25, 13, lap-1, 0, 0, time.UTC).Format(time.RFC3339),
+			LapDuration:  75,
+		}); err != nil {
+			t.Fatalf("UpsertLap(%d) error = %v", lap, err)
+		}
+	}
+	for _, sample := range []store.PositionSample{
+		{SessionKey: sessionKey, DriverNumber: 1, MeetingKey: meetingKey, Date: "2025-05-25T13:00:00Z", Position: 1},
+		{SessionKey: sessionKey, DriverNumber: 16, MeetingKey: meetingKey, Date: "2025-05-25T13:00:00Z", Position: 4},
+		{SessionKey: sessionKey, DriverNumber: 55, MeetingKey: meetingKey, Date: "2025-05-25T13:00:00Z", Position: 3},
+		{SessionKey: sessionKey, DriverNumber: 16, MeetingKey: meetingKey, Date: "2025-05-25T13:05:00Z", Position: 3},
+		{SessionKey: sessionKey, DriverNumber: 55, MeetingKey: meetingKey, Date: "2025-05-25T13:05:00Z", Position: 4},
+	} {
+		if err := st.UpsertPositionSample(sample); err != nil {
+			t.Fatalf("UpsertPositionSample() error = %v", err)
+		}
+	}
+
+	srv := testServer(t, st)
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/race-hub?session_key=9472", nil)
+	rec := httptest.NewRecorder()
+	srv.handleRaceHub(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", rec.Code)
+	}
+
+	var hub query.RaceHub
+	if err := json.Unmarshal(rec.Body.Bytes(), &hub); err != nil {
+		t.Fatalf("decode response: %v", err)
+	}
+	if len(hub.Chapters) == 0 {
+		t.Fatalf("chapters = %+v, want generated chapters", hub.Chapters)
+	}
+	if hub.Chapters[0].Kind != "start" {
+		t.Fatalf("first chapter = %+v, want start", hub.Chapters[0])
+	}
+	foundSwing := false
+	for _, chapter := range hub.Chapters {
+		if chapter.Kind == "decisive_swing" {
+			foundSwing = true
+		}
+	}
+	if !foundSwing {
+		t.Fatalf("chapters = %+v, want decisive_swing", hub.Chapters)
+	}
+}
+
 func TestHandleMeetingsSourceLocal(t *testing.T) {
 	st := openTestStore(t)
 	seedRaceHubStore(t, st)

internal/web/replay.go

@@ -0,0 +1,259 @@
+package web
+
+import (
+	"context"
+	"errors"
+	"math"
+	"net/http"
+	"sort"
+	"strconv"
+	"sync"
+	"time"
+
+	"github.com/AmanTahiliani/box-box/internal/models"
+)
+
+const (
+	defaultReplayIntervalMS = 5000
+	maxReplayFrames         = 3000
+	replayFetchConcurrency  = 4
+)
+
+type replayDataClient interface {
+	GetDriversForSession(sessionKey int) ([]models.Driver, error)
+	GetLocation(sessionKey, driverNumber int) ([]models.Location, error)
+}
+
+type replayFramesResponse struct {
+	SessionKey int           `json:"session_key"`
+	Interval   int           `json:"interval_ms"`
+	StartTime  string        `json:"start_time"`
+	Frames     []replayFrame `json:"frames"`
+}
+
+type replayFrame struct {
+	T    int64                `json:"t"`
+	Cars map[string]replayCar `json:"cars"`
+}
+
+type replayCar struct {
+	X float64 `json:"x"`
+	Y float64 `json:"y"`
+}
+
+func (s *Server) handleReplayFrames(w http.ResponseWriter, r *http.Request) {
+	sessionKey, err := strconv.Atoi(r.URL.Query().Get("session_key"))
+	if err != nil || sessionKey == 0 {
+		http.Error(w, "session_key required", http.StatusBadRequest)
+		return
+	}
+
+	intervalMS := defaultReplayIntervalMS
+	rawInterval := r.URL.Query().Get("interval_ms")
+	if rawInterval != "" {
+		parsed, err := strconv.Atoi(rawInterval)
+		if err != nil {
+			http.Error(w, "invalid interval_ms", http.StatusBadRequest)
+			return
+		}
+		if parsed > intervalMS {
+			intervalMS = parsed
+		}
+	}
+
+	resp, err := assembleReplayFrames(r.Context(), s.client, sessionKey, intervalMS)
+	if err != nil {
+		writeError(w, err, http.StatusInternalServerError, s.client.LastResponseWasStale())
+		return
+	}
+	writeJSON(w, resp)
+}
+
+func assembleReplayFrames(ctx context.Context, client replayDataClient, sessionKey, intervalMS int) (replayFramesResponse, error) {
+	if intervalMS < defaultReplayIntervalMS {
+		intervalMS = defaultReplayIntervalMS
+	}
+
+	resp := replayFramesResponse{
+		SessionKey: sessionKey,
+		Interval:   intervalMS,
+		Frames:     []replayFrame{},
+	}
+
+	drivers, err := client.GetDriversForSession(sessionKey)
+	if err != nil {
+		return resp, err
+	}
+
+	driverNumbers := uniqueDriverNumbers(drivers)
+	if len(driverNumbers) == 0 {
+		return resp, nil
+	}
+
+	series, err := fetchReplayLocationSeries(ctx, client, sessionKey, driverNumbers)
+	if err != nil && len(series) == 0 {
+		return resp, err
+	}
+
+	start, ok := earliestReplayLocationTime(series)
+	if !ok {
+		return resp, nil
+	}
+	resp.StartTime = start.Format(time.RFC3339Nano)
+	resp.Frames = snapReplayFrames(series, start, intervalMS)
+	return resp, nil
+}
+
+func uniqueDriverNumbers(drivers []models.Driver) []int {
+	seen := make(map[int]bool, len(drivers))
+	numbers := make([]int, 0, len(drivers))
+	for _, driver := range drivers {
+		if driver.DriverNumber <= 0 || seen[driver.DriverNumber] {
+			continue
+		}
+		seen[driver.DriverNumber] = true
+		numbers = append(numbers, driver.DriverNumber)
+	}
+	sort.Ints(numbers)
+	return numbers
+}
+
+func fetchReplayLocationSeries(ctx context.Context, client replayDataClient, sessionKey int, driverNumbers []int) (map[int][]models.Location, error) {
+	type result struct {
+		driver int
+		locs   []models.Location
+		err    error
+	}
+
+	sem := make(chan struct{}, replayFetchConcurrency)
+	results := make(chan result, len(driverNumbers))
+	var wg sync.WaitGroup
+
+	for _, driverNumber := range driverNumbers {
+		driverNumber := driverNumber
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			select {
+			case sem <- struct{}{}:
+				defer func() { <-sem }()
+			case <-ctx.Done():
+				results <- result{driver: driverNumber, err: ctx.Err()}
+				return
+			}
+
+			locs, err := client.GetLocation(sessionKey, driverNumber)
+			results <- result{driver: driverNumber, locs: locs, err: err}
+		}()
+	}
+
+	wg.Wait()
+	close(results)
+
+	series := make(map[int][]models.Location, len(driverNumbers))
+	var joined error
+	for result := range results {
+		if result.err != nil {
+			joined = errors.Join(joined, result.err)
+			continue
+		}
+		if len(result.locs) > 0 {
+			series[result.driver] = result.locs
+		}
+	}
+	return series, joined
+}
+
+func earliestReplayLocationTime(series map[int][]models.Location) (time.Time, bool) {
+	var start time.Time
+	for _, locs := range series {
+		for _, loc := range locs {
+			t, err := time.Parse(time.RFC3339Nano, loc.Date)
+			if err != nil {
+				continue
+			}
+			if start.IsZero() || t.Before(start) {
+				start = t
+			}
+		}
+	}
+	if start.IsZero() {
+		return time.Time{}, false
+	}
+	return start, true
+}
+
+func snapReplayFrames(series map[int][]models.Location, start time.Time, intervalMS int) []replayFrame {
+	type accumulator struct {
+		t       int64
+		cars    map[string]replayCar
+		nearest map[string]int64
+	}
+
+	interval := int64(intervalMS)
+	framesByIndex := make(map[int]*accumulator)
+
+	for driverNumber, locs := range series {
+		driverKey := strconv.Itoa(driverNumber)
+		for _, loc := range locs {
+			if !isFiniteFloat(loc.X) || !isFiniteFloat(loc.Y) {
+				continue
+			}
+			t, err := time.Parse(time.RFC3339Nano, loc.Date)
+			if err != nil {
+				continue
+			}
+			offset := t.Sub(start).Milliseconds()
+			if offset < 0 {
+				continue
+			}
+			index := int((offset + interval/2) / interval)
+			if index < 0 || index >= maxReplayFrames {
+				continue
+			}
+			frameT := int64(index) * interval
+			distance := absInt64(offset - frameT)
+
+			acc, ok := framesByIndex[index]
+			if !ok {
+				acc = &accumulator{
+					t:       frameT,
+					cars:    make(map[string]replayCar),
+					nearest: make(map[string]int64),
+				}
+				framesByIndex[index] = acc
+			}
+			if prev, ok := acc.nearest[driverKey]; ok && prev <= distance {
+				continue
+			}
+			acc.nearest[driverKey] = distance
+			acc.cars[driverKey] = replayCar{X: loc.X, Y: loc.Y}
+		}
+	}
+
+	indexes := make([]int, 0, len(framesByIndex))
+	for index, acc := range framesByIndex {
+		if len(acc.cars) > 0 {
+			indexes = append(indexes, index)
+		}
+	}
+	sort.Ints(indexes)
+
+	frames := make([]replayFrame, 0, len(indexes))
+	for _, index := range indexes {
+		acc := framesByIndex[index]
+		frames = append(frames, replayFrame{T: acc.t, Cars: acc.cars})
+	}
+	return frames
+}
+
+func absInt64(v int64) int64 {
+	if v < 0 {
+		return -v
+	}
+	return v
+}
+
+func isFiniteFloat(v float64) bool {
+	return !math.IsNaN(v) && !math.IsInf(v, 0)
+}

internal/web/replay_test.go

@@ -0,0 +1,181 @@
+package web
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/AmanTahiliani/box-box/internal/models"
+)
+
+type fakeReplayClient struct {
+	drivers []models.Driver
+	locs    map[int][]models.Location
+	err     error
+
+	mu          sync.Mutex
+	inFlight    int
+	maxInFlight int
+	delay       time.Duration
+}
+
+func (f *fakeReplayClient) GetDriversForSession(sessionKey int) ([]models.Driver, error) {
+	if f.err != nil {
+		return nil, f.err
+	}
+	return f.drivers, nil
+}
+
+func (f *fakeReplayClient) GetLocation(sessionKey, driverNumber int) ([]models.Location, error) {
+	f.mu.Lock()
+	f.inFlight++
+	if f.inFlight > f.maxInFlight {
+		f.maxInFlight = f.inFlight
+	}
+	f.mu.Unlock()
+
+	if f.delay > 0 {
+		time.Sleep(f.delay)
+	}
+
+	f.mu.Lock()
+	f.inFlight--
+	f.mu.Unlock()
+
+	return f.locs[driverNumber], nil
+}
+
+func TestAssembleReplayFramesSnapsNearestSamplesAndOmitsEmptyDrivers(t *testing.T) {
+	start := time.Date(2025, 5, 25, 13, 0, 0, 0, time.UTC)
+	client := &fakeReplayClient{
+		drivers: []models.Driver{
+			{DriverNumber: 1},
+			{DriverNumber: 4},
+			{DriverNumber: 16},
+		},
+		locs: map[int][]models.Location{
+			1: {
+				{Date: start.Add(1 * time.Second).Format(time.RFC3339Nano), X: 10, Y: 20},
+				{Date: start.Add(4 * time.Second).Format(time.RFC3339Nano), X: 40, Y: 80},
+				{Date: start.Add(6 * time.Second).Format(time.RFC3339Nano), X: 60, Y: 120},
+			},
+			4: {
+				{Date: start.Add(5 * time.Second).Format(time.RFC3339Nano), X: 100, Y: 200},
+			},
+			16: {},
+		},
+	}
+
+	resp, err := assembleReplayFrames(context.Background(), client, 99, 5000)
+	if err != nil {
+		t.Fatalf("assembleReplayFrames() error = %v", err)
+	}
+	if resp.SessionKey != 99 || resp.Interval != 5000 {
+		t.Fatalf("response metadata = %+v", resp)
+	}
+	if resp.StartTime != start.Add(1*time.Second).Format(time.RFC3339Nano) {
+		t.Fatalf("start_time = %q", resp.StartTime)
+	}
+	if len(resp.Frames) != 2 {
+		t.Fatalf("frames len = %d, want 2: %+v", len(resp.Frames), resp.Frames)
+	}
+	if _, ok := resp.Frames[0].Cars["16"]; ok {
+		t.Fatalf("empty driver included in frame: %+v", resp.Frames[0].Cars)
+	}
+	if got := resp.Frames[0].Cars["1"]; got.X != 10 || got.Y != 20 {
+		t.Fatalf("frame 0 car 1 = %+v, want first nearest sample", got)
+	}
+	if got := resp.Frames[1].Cars["1"]; got.X != 60 || got.Y != 120 {
+		t.Fatalf("frame 1 car 1 = %+v, want later nearest sample", got)
+	}
+	if got := resp.Frames[1].Cars["4"]; got.X != 100 || got.Y != 200 {
+		t.Fatalf("frame 1 car 4 = %+v", got)
+	}
+}
+
+func TestAssembleReplayFramesCapsFrameCount(t *testing.T) {
+	start := time.Date(2025, 5, 25, 13, 0, 0, 0, time.UTC)
+	locs := make([]models.Location, maxReplayFrames+250)
+	for i := range locs {
+		locs[i] = models.Location{
+			Date: start.Add(time.Duration(i*defaultReplayIntervalMS) * time.Millisecond).Format(time.RFC3339Nano),
+			X:    float64(i),
+			Y:    float64(i * 2),
+		}
+	}
+	client := &fakeReplayClient{
+		drivers: []models.Driver{{DriverNumber: 1}},
+		locs:    map[int][]models.Location{1: locs},
+	}
+
+	resp, err := assembleReplayFrames(context.Background(), client, 99, defaultReplayIntervalMS)
+	if err != nil {
+		t.Fatalf("assembleReplayFrames() error = %v", err)
+	}
+	if len(resp.Frames) > maxReplayFrames {
+		t.Fatalf("frames len = %d, want <= %d", len(resp.Frames), maxReplayFrames)
+	}
+	if len(resp.Frames) != maxReplayFrames {
+		t.Fatalf("frames len = %d, want hard cap %d", len(resp.Frames), maxReplayFrames)
+	}
+}
+
+func TestAssembleReplayFramesBoundsLocationFanOut(t *testing.T) {
+	drivers := make([]models.Driver, 10)
+	locs := make(map[int][]models.Location, len(drivers))
+	now := time.Date(2025, 5, 25, 13, 0, 0, 0, time.UTC)
+	for i := range drivers {
+		number := i + 1
+		drivers[i] = models.Driver{DriverNumber: number}
+		locs[number] = []models.Location{{Date: now.Format(time.RFC3339Nano), X: float64(number), Y: float64(number)}}
+	}
+	client := &fakeReplayClient{
+		drivers: drivers,
+		locs:    locs,
+		delay:   5 * time.Millisecond,
+	}
+
+	if _, err := assembleReplayFrames(context.Background(), client, 99, defaultReplayIntervalMS); err != nil {
+		t.Fatalf("assembleReplayFrames() error = %v", err)
+	}
+	if client.maxInFlight > replayFetchConcurrency {
+		t.Fatalf("max in-flight location calls = %d, want <= %d", client.maxInFlight, replayFetchConcurrency)
+	}
+}
+
+func TestHandleReplayFramesValidatesParamsAndFloorsInterval(t *testing.T) {
+	srv := testServer(t, nil)
+
+	req := httptest.NewRequest(http.MethodGet, "/api/v1/replay/frames", nil)
+	rec := httptest.NewRecorder()
+	srv.handleReplayFrames(rec, req)
+	if rec.Code != http.StatusBadRequest {
+		t.Fatalf("missing session_key status = %d, want 400", rec.Code)
+	}
+
+	req = httptest.NewRequest(http.MethodGet, "/api/v1/replay/frames?session_key=1&interval_ms=nope", nil)
+	rec = httptest.NewRecorder()
+	srv.handleReplayFrames(rec, req)
+	if rec.Code != http.StatusBadRequest {
+		t.Fatalf("invalid interval status = %d, want 400", rec.Code)
+	}
+
+	client := &fakeReplayClient{drivers: []models.Driver{{DriverNumber: 1}}, locs: map[int][]models.Location{
+		1: {{Date: time.Date(2025, 5, 25, 13, 0, 0, 0, time.UTC).Format(time.RFC3339Nano), X: 1, Y: 2}},
+	}}
+	resp, err := assembleReplayFrames(context.Background(), client, 99, 1000)
+	if err != nil {
+		t.Fatalf("assembleReplayFrames() error = %v", err)
+	}
+	body, err := json.Marshal(resp)
+	if err != nil || len(body) == 0 {
+		t.Fatalf("marshal response = %d bytes, %v", len(body), err)
+	}
+	if resp.Interval != defaultReplayIntervalMS {
+		t.Fatalf("interval = %d, want floor %d", resp.Interval, defaultReplayIntervalMS)
+	}
+}

internal/web/server.go

@@ -70,11 +70,15 @@ func (s *Server) routes() (http.Handler, error) {
 	mux.HandleFunc("/api/v1/news", s.handleNews)
 	mux.HandleFunc("/api/v1/meetings", s.handleMeetings)
 	mux.HandleFunc("/api/v1/sessions", s.handleSessions)
+	// /api/v1/driver/summary before /api/v1/drivers: distinct prefixes today,
+	// but keep the more specific driver/* paths registered first.
+	mux.HandleFunc("/api/v1/driver/summary", s.handleDriverSummary)
 	mux.HandleFunc("/api/v1/drivers", s.handleDrivers)
 	mux.HandleFunc("/api/v1/results", s.handleResults)
 	mux.HandleFunc("/api/v1/grid", s.handleGrid)
 	mux.HandleFunc("/api/v1/laps/comparison", s.handleLapsComparison)
 	mux.HandleFunc("/api/v1/laps", s.handleLaps)
+	mux.HandleFunc("/api/v1/replay/frames", s.handleReplayFrames)
 	mux.HandleFunc("/api/v1/weather", s.handleWeather)
 	mux.HandleFunc("/api/v1/race-control", s.handleRaceControl)
 	mux.HandleFunc("/api/v1/telemetry", s.handleTelemetry)