Merge pull request #88 from AmanTahiliani/feat/issue-87-live-correct-fp-q-timing-truth-hierarchy

[Live] Correct FP/Q timing truth, hierarchy, and mobile navigation (#87)

frontend/src/api.ts

@@ -11,6 +11,7 @@ import type {
   Meeting,
   NewsItem,
   RaceHub,
+  ReplayFramesResponse,
   Session,
   TrackOutline,
   Weekend,
@@ -81,6 +82,21 @@ export async function fetchTrackOutline(circuitKey: number, year: number): Promi
   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) {

frontend/src/components/ChapterStrip.tsx

@@ -0,0 +1,116 @@
+import { useEffect, useRef } from 'react'
+import { BookOpen } from 'lucide-react'
+import type { Chapter } from '../types'
+import {
+  activeChapterIndex,
+  chapterKindLabel,
+  chapterLapRange,
+  chapterStartScrub,
+} from '../lib/chapters'
+import { EmptyStateCard } from './EmptyStateCard'
+import '../styles/chapters.css'
+
+interface Props {
+  chapters: Chapter[]
+  scrubTime: number | null
+  tMin: number
+  tRange: number
+  tourActive: boolean
+  tourChapterIndex: number | null
+  /** Explicit selection from a chapter click; wins over scrub-derived active. */
+  selectedChapterIndex?: number | null
+  onChapterClick: (index: number, scrub: number) => void
+  onTourToggle: () => void
+}
+
+export function ChapterStrip({
+  chapters,
+  scrubTime,
+  tMin,
+  tRange,
+  tourActive,
+  tourChapterIndex,
+  selectedChapterIndex = null,
+  onChapterClick,
+  onTourToggle,
+}: Props) {
+  const scrollRef = useRef<HTMLDivElement>(null)
+  const activeIndex = activeChapterIndex(chapters, scrubTime, tMin, tRange)
+  const highlightedIndex = tourActive
+    ? tourChapterIndex
+    : (selectedChapterIndex ?? activeIndex)
+
+  useEffect(() => {
+    if (highlightedIndex === null || !scrollRef.current) return
+    const card = scrollRef.current.querySelector<HTMLElement>(
+      `[data-testid="chapter-card-${highlightedIndex}"]`,
+    )
+    card?.scrollIntoView?.({ behavior: 'smooth', inline: 'center', block: 'nearest' })
+  }, [highlightedIndex])
+
+  if (chapters.length === 0) {
+    return (
+      <div className="chapter-strip" data-testid="chapter-strip">
+        <EmptyStateCard
+          icon={BookOpen}
+          title="No story chapters"
+          hint="This session does not have enough race-control or position data to build narrative chapters."
+          testId="chapter-strip-empty"
+          className="chapter-strip-empty-card"
+        />
+      </div>
+    )
+  }
+
+  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 ${tourActive ? 'active' : ''}`}
+            onClick={onTourToggle}
+            aria-pressed={tourActive}
+          >
+            {tourActive ? 'Exit 90s' : '90s tour'}
+          </button>
+        </div>
+      </div>
+      <div className="chapter-strip-scroll-wrap">
+        <div
+          ref={scrollRef}
+          className="chapter-strip-scroll"
+          role="list"
+          aria-label="Race story chapters"
+        >
+          {chapters.map((chapter, index) => {
+            const scrub = chapterStartScrub(chapter, tMin, tRange) ?? index / Math.max(chapters.length - 1, 1)
+            const isActive = highlightedIndex === index
+            const headline = chapter.headline || chapter.title
+
+            return (
+              <button
+                key={`${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>
+    </div>
+  )
+}

frontend/src/components/EmptyStateCard.tsx

@@ -0,0 +1,20 @@
+import type { LucideIcon } from 'lucide-react'
+import type { ReactNode } from 'react'
+
+interface Props {
+  icon: LucideIcon
+  title: string
+  hint: ReactNode
+  testId?: string
+  className?: string
+}
+
+export function EmptyStateCard({ icon: Icon, title, hint, testId, className = '' }: Props) {
+  return (
+    <div className={`empty-state ui-card ${className}`.trim()} data-testid={testId}>
+      <Icon size={32} className="empty-state-icon" aria-hidden />
+      <div className="empty-state-title">{title}</div>
+      <div className="empty-state-desc">{hint}</div>
+    </div>
+  )
+}

frontend/src/components/Nav.tsx

@@ -1,6 +1,17 @@
 import { Link } from '@tanstack/react-router'
+import { useQuery } from '@tanstack/react-query'
+import { fetchLiveState } from '../api'
+import { isLiveSessionActive } from '../lib/live'
 
 export function Nav() {
+  const { data: liveState } = useQuery({
+    queryKey: ['live-state'],
+    queryFn: fetchLiveState,
+    staleTime: 5_000,
+    refetchInterval: 30_000,
+  })
+  const liveActive = isLiveSessionActive(liveState)
+
   return (
     <nav className="app-nav">
       <Link to="/" className="nav-logo">
@@ -10,8 +21,16 @@ export function Nav() {
         <Link to="/" activeProps={{ className: 'active' }} activeOptions={{ exact: true }}>
           Command
         </Link>
-        <Link to="/live" activeProps={{ className: 'active' }}>
+        <Link
+          to="/live"
+          className={liveActive ? 'nav-live nav-live-on' : 'nav-live'}
+          activeProps={{ className: 'active' }}
+          data-testid="nav-live"
+          data-live-active={liveActive ? 'true' : 'false'}
+        >
+          {liveActive && <span className="nav-live-dot" aria-hidden="true" />}
           Live
+          {liveActive && <span className="sr-only"> session active</span>}
         </Link>
         <Link to="/race-hub" search={{}} activeProps={{ className: 'active' }}>
           Race Hub

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 +1,36 @@
-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 { LineChart } from 'lucide-react'
+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 { EmptyStateCard } from './EmptyStateCard'
 import { gridDelta, gridDeltaClass, formatDuration, formatGap } from '../utils'
+import {
+  chapterBandFill,
+  chapterEndScrub,
+  chapterStartScrub,
+  chapterTourDurations,
+  deCollideYPositions,
+  decimatedPositionLabels,
+} from '../lib/chapters'
+import { isReplayMapAvailable } from '../lib/replayMap'
+import '../styles/race-story.css'
+
+const CHAPTER_TOUR_MS = 90_000
+const CHART_W = 640
+const CHART_H = 180
+const CHART_PL = 40
+const CHART_PR = 48
+const CHART_PT = 8
+const CHART_PB = 20
+
+interface ChartTiming {
+  tMin: number
+  tMax: number
+  tRange: number
+}
 
 interface Props {
   data: {
@@ -12,38 +42,256 @@ interface Props {
     race_control?: any[]
     pit_stops?: any[]
     session?: Session
+    meeting?: Meeting
+    drivers?: Driver[]
+    chapters?: Chapter[]
   }
 }
 
+/**
+ * Position samples are recorded for the entire session, including the pre-race
+ * grid period.  Use the winning driver's laps to define the race window so
+ * that the x-axis starts at lights-out rather than at the earliest sample.
+ */
+function raceChartTiming(
+  positions: PositionSample[],
+  laps: Lap[],
+  results: EnrichedResult[],
+): ChartTiming | null {
+  const positionTimes = positions
+    .map((position) => new Date(position.date).getTime())
+    .filter(Number.isFinite)
+  if (positionTimes.length === 0) return null
+
+  const fallbackMin = Math.min(...positionTimes)
+  const fallbackMax = Math.max(...positionTimes)
+  const fallback = {
+    tMin: fallbackMin,
+    tMax: fallbackMax,
+    tRange: Math.max(fallbackMax - fallbackMin, 1),
+  }
+
+  const winner = results.find((result) => result.position === 1)
+  if (!winner) return fallback
+
+  const winnerLaps = laps
+    .filter((lap) => lap.driver_number === winner.driver_number && lap.lap_number > 0)
+    .map((lap) => ({ ...lap, start: new Date(lap.date_start).getTime() }))
+    .filter((lap) => Number.isFinite(lap.start))
+    .sort((a, b) => a.lap_number - b.lap_number)
+  if (winnerLaps.length === 0) return fallback
+
+  const firstLap = winnerLaps[0]
+  const lastLap = winnerLaps[winnerLaps.length - 1]
+  const finalLapDuration = lastLap.lap_duration ?? 0
+  const tMax = lastLap.start + (finalLapDuration > 0 ? finalLapDuration * 1000 : 0)
+  if (tMax <= firstLap.start) return fallback
+
+  return { tMin: firstLap.start, tMax, tRange: tMax - firstLap.start }
+}
+
 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 [selectedChapterIndex, setSelectedChapterIndex] = 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(() => raceChartTiming(positions, laps, results), [laps, positions, results])
+  const hasChartData = hasPositions && chartTiming !== null
+  const circuitKey = session?.circuit_key ?? meeting?.circuit_key ?? 0
+  const outlineYear = meeting?.year ?? (session?.date_start ? new Date(session.date_start).getFullYear() : 0)
+  const canProbeMap = Boolean(session?.session_key) && circuitKey > 0 && outlineYear > 0
+
+  const replayQuery = useQuery({
+    queryKey: ['replay-frames', session?.session_key, 5000],
+    queryFn: () => fetchReplayFrames(session!.session_key, 5000),
+    enabled: canProbeMap,
+  })
+  const outlineQuery = useQuery({
+    queryKey: ['track-outline', circuitKey, outlineYear],
+    queryFn: () => fetchTrackOutline(circuitKey, outlineYear),
+    enabled: canProbeMap,
+  })
+
+  const mapProbeSettled = !canProbeMap || (!replayQuery.isLoading && !outlineQuery.isLoading)
+  const mapAvailable = useMemo(
+    () =>
+      canProbeMap &&
+      isReplayMapAvailable(
+        replayQuery.data,
+        outlineQuery.data,
+        replayQuery.isError || outlineQuery.isError,
+      ),
+    [canProbeMap, outlineQuery.data, outlineQuery.isError, replayQuery.data, replayQuery.isError],
+  )
+  const showMapPanel = mapOpen && mapAvailable
+
+  useEffect(() => {
+    if (!mapAvailable && mapOpen) {
+      setMapOpen(false)
+    }
+  }, [mapAvailable, mapOpen])
+
+  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()
+    setSelectedChapterIndex(index)
+    setScrubTime(scrub)
+  }
+
+  const clearChapterSelection = () => {
+    setSelectedChapterIndex(null)
+  }
+
+  const toggleChapterTour = () => {
+    if (chapterTourActive) {
+      stopChapterTour()
+      return
+    }
+    if (!chartTiming || chapters.length === 0) return
+    setIsPlaying(false)
+    setSelectedChapterIndex(null)
+    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 normaliseTime = (time: number) => Math.max(0, Math.min(1, (time - tMin) / tRange))
 
     const byDriver = new Map<number, Array<{ t: number; pos: number }>>()
     for (const p of positions) {
+      const time = new Date(p.date).getTime()
+      if (!Number.isFinite(time)) continue
       if (!byDriver.has(p.driver_number)) byDriver.set(p.driver_number, [])
       byDriver.get(p.driver_number)!.push({
-        t: (new Date(p.date).getTime() - tMin) / tRange,
+        t: normaliseTime(time),
         pos: p.position,
       })
     }
-    const dnfSet = new Set(results.filter(r => r.dnf || r.dns || r.dsq).map(r => r.driver_number))
+    const dnfSet = new Set(results.filter((r) => r.dnf || r.dns || r.dsq).map((r) => r.driver_number))
     for (const [dNum, samples] of byDriver.entries()) {
       samples.sort((a, b) => a.t - b.t)
       if (samples.length > 0 && !dnfSet.has(dNum)) {
@@ -51,16 +299,16 @@ export function RaceStoryCanvas({ data }: Props) {
       }
     }
 
-    const getInterpPos = (samples: {t: number, pos: number}[], t: number) => {
+    const getInterpPos = (samples: { t: number; pos: number }[], t: number) => {
       if (!samples || samples.length === 0) return null
       if (t <= samples[0].t) return samples[0].pos
       if (t >= samples[samples.length - 1].t) return samples[samples.length - 1].pos
       for (let i = 0; i < samples.length - 1; i++) {
-        if (samples[i].t <= t && samples[i+1].t >= t) {
-          const dt = samples[i+1].t - samples[i].t
+        if (samples[i].t <= t && samples[i + 1].t >= t) {
+          const dt = samples[i + 1].t - samples[i].t
           if (dt === 0) return samples[i].pos
           const frac = (t - samples[i].t) / dt
-          return samples[i].pos + (samples[i+1].pos - samples[i].pos) * frac
+          return samples[i].pos + (samples[i + 1].pos - samples[i].pos) * frac
         }
       }
       return null
@@ -84,43 +332,46 @@ export function RaceStoryCanvas({ data }: Props) {
     const maxPos = Math.max(...positions.map((p) => p.position), results.length, 2)
     const colorByDriver = new Map(results.map((r) => [r.driver_number, r.team_colour]))
     const acronymByDriver = new Map(results.map((r) => [r.driver_number, r.name_acronym]))
+    const positionLabels = decimatedPositionLabels(maxPos)
 
-    const W = 640
-    const H = 180
-    const PL = 40
-    const PR = 48
-    const PT = 8
-    const PB = 20
+    const W = CHART_W
+    const H = CHART_H
+    const PL = CHART_PL
+    const PR = CHART_PR
+    const PT = CHART_PT
+    const PB = CHART_PB
     const plotW = W - PL - PR
     const plotH = H - PT - PB
 
     const toX = (t: number) => PL + t * plotW
     const toY = (pos: number) => PT + ((pos - 1) / Math.max(maxPos - 1, 1)) * plotH
 
-    const winner = results.find(r => r.position === 1)
-    const winnerLaps = winner ? laps.filter(l => l.driver_number === winner.driver_number) : []
-    const lapTicks: { lap: number, t: number }[] = []
+    const winner = results.find((r) => r.position === 1)
+    const winnerLaps = winner ? laps.filter((l) => l.driver_number === winner.driver_number) : []
+    const lapTicks: { lap: number; t: number }[] = []
     const lapInterval = winnerLaps.length < 30 ? 5 : 10
-    
-    for (const lap of winnerLaps) {
+
+    for (let i = 0; i < winnerLaps.length; i++) {
+      const lap = winnerLaps[i]
       if (lap.lap_number > 0 && lap.lap_number % lapInterval === 0) {
-        const t = (new Date(lap.date_start).getTime() - tMin) / tRange
-        if (t >= 0 && t <= 1) {
-          lapTicks.push({ lap: lap.lap_number, t })
-        }
+        const lapStart = new Date(lap.date_start).getTime()
+        const nextLapStart = winnerLaps[i + 1] ? new Date(winnerLaps[i + 1].date_start).getTime() : NaN
+        const lapEnd = lap.lap_duration && lap.lap_duration > 0
+          ? lapStart + lap.lap_duration * 1000
+          : nextLapStart
+        if (Number.isFinite(lapEnd)) lapTicks.push({ lap: lap.lap_number, t: normaliseTime(lapEnd) })
       }
     }
 
-    // Safety Car / VSC periods
     const scPeriods: { start: number; end: number | null; type: 'SC' | 'VSC' }[] = []
     let activeSC: { start: number; type: 'SC' | 'VSC' } | null = null
     const rc = [...race_control].sort((a, b) => new Date(a.date).getTime() - new Date(b.date).getTime())
-    
+
     for (const msg of rc) {
       const t = new Date(msg.date).getTime()
       const m = msg.message?.toUpperCase() || ''
       const cat = msg.category?.toUpperCase() || ''
-      
+
       if (m.includes('VIRTUAL SAFETY CAR DEPLOYED') || cat === 'VIRTUALSAFETYCAR') {
         if (!activeSC) activeSC = { start: t, type: 'VSC' }
       } else if (m.includes('SAFETY CAR DEPLOYED') || cat === 'SAFETYCAR') {
@@ -136,23 +387,73 @@ export function RaceStoryCanvas({ data }: Props) {
       scPeriods.push({ start: activeSC.start, end: null, type: activeSC.type })
     }
 
+    const chapterBands = chapters
+      .map((chapter, index) => {
+        const startT = chapterStartScrub(chapter, tMin, tRange)
+        const endT = chapterEndScrub(chapter, tMin, tRange)
+        if (startT === null) return null
+        const end = endT ?? startT
+        return {
+          key: `${chapter.kind}-${index}`,
+          start: Math.min(startT, end),
+          end: Math.max(startT, end),
+          fill: chapterBandFill(chapter.kind),
+        }
+      })
+      .filter((band): band is NonNullable<typeof band> => band !== null)
+
+    const labelCandidates = Array.from(byDriver.entries())
+      .map(([dNum, samples]) => {
+        const last = samples[samples.length - 1]
+        if (!last) return null
+        return { key: dNum, y: toY(last.pos) }
+      })
+      .filter((item): item is { key: number; y: number } => item !== null)
+    const labelYByDriver = deCollideYPositions(labelCandidates, 12)
+
     const handlePointerMove = (e: React.PointerEvent<SVGRectElement>) => {
+      setIsPlaying(false)
+      stopChapterTour()
+      clearChapterSelection()
       if (!svgRef.current) return
       const rect = svgRef.current.getBoundingClientRect()
-      const x = e.clientX - rect.left
+      if (rect.width <= 0) return
+      // Pointer coordinates are CSS pixels; convert them to the SVG viewBox
+      // before comparing with the fixed chart margins and plot width.
+      const x = ((e.clientX - rect.left) / rect.width) * W
       const t = Math.max(0, Math.min(1, (x - PL) / plotW))
       setScrubTime(t)
     }
 
     chartContent = (
-      <div className="rs-chart-container scroll-x" data-testid="position-chart">
+      <div
+        className={`rs-chart-container scroll-x${showMapPanel ? '' : ' rs-chart-container--full'}`}
+        data-testid="position-chart"
+      >
         <svg
           ref={svgRef}
+          className="rs-position-chart-svg"
           viewBox={`0 0 ${W} ${H}`}
-          style={{ width: '100%', minWidth: 280, maxWidth: W, display: 'block' }}
           role="img"
           aria-label="Position evolution chart"
         >
+          {chapterBands.map((band) => {
+            const x1 = toX(Math.max(0, band.start))
+            const x2 = toX(Math.min(1, band.end))
+            if (x2 <= PL || x1 >= W - PR) return null
+            return (
+              <rect
+                key={band.key}
+                x={x1}
+                y={PT}
+                width={Math.max(0, x2 - x1)}
+                height={plotH}
+                fill={band.fill}
+                data-testid="chapter-band"
+              />
+            )
+          })}
+
           {scPeriods.map((sc, i) => {
             const startT = (sc.start - tMin) / tRange
             const endT = sc.end ? (sc.end - tMin) / tRange : 1
@@ -171,33 +472,41 @@ export function RaceStoryCanvas({ data }: Props) {
             )
           })}
 
-          {Array.from({ length: maxPos }, (_, i) => i + 1).map((pos) => (
+          {positionLabels.map((pos) => (
             <g key={pos}>
               <line
                 x1={PL}
                 x2={W - PR}
                 y1={toY(pos)}
                 y2={toY(pos)}
-                stroke="var(--border)"
-                strokeWidth={0.5}
+                className="rs-chart-grid-line"
               />
               <text
                 x={PL - 4}
                 y={toY(pos) + 4}
                 textAnchor="end"
-                fill="var(--text-3)"
-                fontSize={8}
-                fontFamily="var(--f-mono)"
+                className="rs-chart-axis-label"
               >
                 P{pos}
               </text>
             </g>
           ))}
 
-          {lapTicks.map(tick => (
+          {lapTicks.map((tick) => (
             <g key={`lap-${tick.lap}`}>
-              <line x1={toX(tick.t)} x2={toX(tick.t)} y1={H - PB} y2={H - PB + 4} stroke="var(--border)" strokeWidth={1} />
-              <text x={toX(tick.t)} y={H - PB + 14} textAnchor="middle" fill="var(--text-3)" fontSize={9} fontFamily="var(--f-mono)">
+              <line
+                x1={toX(tick.t)}
+                x2={toX(tick.t)}
+                y1={H - PB}
+                y2={H - PB + 4}
+                className="rs-chart-lap-tick"
+              />
+              <text
+                x={toX(tick.t)}
+                y={H - PB + 14}
+                textAnchor="middle"
+                className="rs-chart-axis-label"
+              >
                 L{tick.lap}
               </text>
             </g>
@@ -210,11 +519,12 @@ export function RaceStoryCanvas({ data }: Props) {
             const last = samples[samples.length - 1]
             const isHovered = hoverDriver === dNum
             const isFaded = hoverDriver !== null && !isHovered
+            const labelY = last ? (labelYByDriver.get(dNum) ?? toY(last.pos)) : 0
 
-            const driverPits = pit_stops.filter(p => p.driver_number === dNum)
+            const driverPits = pit_stops.filter((p) => p.driver_number === dNum)
 
             return (
-              <g 
+              <g
                 key={dNum}
                 style={{ opacity: isFaded ? 0.2 : 1, transition: 'opacity 0.2s' }}
                 onMouseEnter={() => setHoverDriver(dNum)}
@@ -230,30 +540,31 @@ export function RaceStoryCanvas({ data }: Props) {
                   className="rs-driver-line"
                   pathLength={1}
                 />
-                
+
                 {driverPits.map((p, i) => {
-                  const t = (new Date(p.date).getTime() - tMin) / tRange
-                  if (t < 0 || t > 1) return null
+                  const time = new Date(p.date).getTime()
+                  if (!Number.isFinite(time) || time < tMin || time > tMin + tRange) return null
+                  const t = normaliseTime(time)
                   const pos = getInterpPos(samples, t)
                   if (pos === null) return null
                   return (
-                    <circle 
-                      key={`pit-${i}`} 
-                      cx={toX(t)} 
-                      cy={toY(pos)} 
-                      r={3} 
-                      fill="var(--bg)" 
-                      stroke={color} 
+                    <circle
+                      key={`pit-${i}`}
+                      cx={toX(t)}
+                      cy={toY(pos)}
+                      r={3}
+                      fill="var(--bg)"
+                      stroke={color}
                       strokeWidth={2}
                       className="rs-pit-dot"
                     />
                   )
                 })}
-                
+
                 {last && (
                   <text
                     x={toX(last.t) + 6}
-                    y={toY(last.pos) + 4}
+                    y={labelY + 4}
                     fill={color}
                     fontSize={isHovered ? 11 : 9}
                     fontFamily="var(--f-mono)"
@@ -287,25 +598,110 @@ export function RaceStoryCanvas({ data }: Props) {
             width={plotW}
             height={plotH}
             fill="transparent"
+            data-testid="position-chart-interaction"
             onPointerMove={handlePointerMove}
-            onPointerLeave={() => setScrubTime(null)}
+            onPointerLeave={() => {
+              if (!isPlaying) {
+                clearChapterSelection()
+                setScrubTime(null)
+              }
+            }}
             style={{ cursor: 'crosshair', touchAction: 'none' }}
           />
         </svg>
+        <div className="rs-segmented-control" aria-label="Race replay controls" data-testid="replay-controls">
+          <button
+            type="button"
+            className={`rs-segment ${isPlaying ? 'active' : ''}`}
+            onClick={() => {
+              setScrubTime((current) => current ?? 0)
+              stopChapterTour()
+              clearChapterSelection()
+              setIsPlaying((current) => !current)
+            }}
+            aria-pressed={isPlaying}
+          >
+            {isPlaying ? 'Pause' : 'Play'}
+          </button>
+          <span className="rs-segment-divider" aria-hidden />
+          {[1, 10, 30].map((speed) => (
+            <button
+              key={speed}
+              type="button"
+              className={`rs-segment ${playbackSpeed === speed ? 'active' : ''}`}
+              onClick={() => setPlaybackSpeed(speed)}
+              aria-pressed={playbackSpeed === speed}
+            >
+              {speed}x
+            </button>
+          ))}
+          {mapProbeSettled && mapAvailable && (
+            <>
+              <span className="rs-segment-divider" aria-hidden />
+              <button
+                type="button"
+                className={`rs-segment ${mapOpen ? 'active' : ''}`}
+                onClick={() => setMapOpen((current) => !current)}
+                aria-pressed={mapOpen}
+                data-testid="replay-map-toggle"
+              >
+                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}
+          selectedChapterIndex={selectedChapterIndex}
+          onChapterClick={jumpToChapter}
+          onTourToggle={toggleChapterTour}
+        />
       )}
+      <div className={`rs-replay-shell${showMapPanel ? ' rs-replay-shell--split' : ''}`}>
+        <div className="rs-replay-main">
+          {hasChartData ? (
+            chartContent
+          ) : (
+            <EmptyStateCard
+              icon={LineChart}
+              title="Lap-by-lap positions not available"
+              hint={
+                <>
+                  This session does not have ingested position samples in{' '}
+                  <code>/api/v1/race-hub</code>.
+                </>
+              }
+              testId="race-story-no-positions"
+              className="race-story-empty-card"
+            />
+          )}
+        </div>
+        {showMapPanel && (
+          <div className="rs-replay-map-slot" data-testid="replay-map-slot">
+            <ReplayTrackMap
+              outline={outlineQuery.data}
+              replay={replayQuery.data}
+              tMs={replayTMs}
+              drivers={drivers}
+              results={results}
+              loading={outlineQuery.isLoading || replayQuery.isLoading}
+              error={outlineQuery.isError || replayQuery.isError}
+            />
+          </div>
+        )}
+      </div>
 
       {displayResults.length > 0 && (
         <div className="rs-field-list">
@@ -313,30 +709,29 @@ export function RaceStoryCanvas({ data }: Props) {
             const gridPos = grid.find((g) => g.driver_number === r.driver_number)?.position ?? 0
             const currentPos = scrubTime !== null ? i + 1 : r.position
             const isWinner = i === 0 && r.position === 1
-            const pClass = currentPos === 1 ? 'rs-pos-p1' : currentPos === 2 ? 'rs-pos-p2' : currentPos === 3 ? 'rs-pos-p3' : ''
-            
+            const pClass =
+              currentPos === 1 ? 'rs-pos-p1' : currentPos === 2 ? 'rs-pos-p2' : currentPos === 3 ? 'rs-pos-p3' : ''
+
             let currentPoints: number | string = r.points
             if (scrubTime !== null) {
               const isSprint = data.session?.session_type?.toLowerCase().includes('sprint')
               const ptsArray = isSprint ? [8, 7, 6, 5, 4, 3, 2, 1] : [25, 18, 15, 12, 10, 8, 6, 4, 2, 1]
               currentPoints = currentPos <= ptsArray.length ? ptsArray[currentPos - 1] : 0
             }
-            
+
             return (
-              <div 
-                key={r.driver_number} 
+              <div
+                key={r.driver_number}
                 className={`rs-driver-row ${hoverDriver === r.driver_number ? 'rs-driver-row-hover' : ''}`}
                 onMouseEnter={() => setHoverDriver(r.driver_number)}
                 onMouseLeave={() => setHoverDriver(null)}
               >
                 <div className="rs-driver-left">
-                  <div className={`rs-pos-col ${pClass}`}>
-                    {currentPos}
-                  </div>
+                  <div className={`rs-pos-col ${pClass}`}>{currentPos}</div>
                   <div className="rs-driver-cell">
-                    <div 
-                      className="rs-driver-color" 
-                      style={{ background: r.team_colour ? `#${r.team_colour}` : 'var(--border)' }} 
+                    <div
+                      className="rs-driver-color"
+                      style={{ background: r.team_colour ? `#${r.team_colour}` : 'var(--border)' }}
                     />
                     <div className="rs-driver-identity">
                       <span className="rs-driver-name">{r.name_acronym || r.driver_number}</span>
@@ -354,12 +749,12 @@ export function RaceStoryCanvas({ data }: Props) {
                     </span>
                     <span className="rs-metric-label">Grid</span>
                   </div>
-                  
+
                   <div className="rs-metric" style={{ width: '80px', opacity: scrubTime !== null ? 0.3 : 1 }}>
                     <span>{isWinner ? formatDuration(r.duration) : formatGap(r.gap_to_leader)}</span>
                     <span className="rs-metric-label">{isWinner ? 'Time' : 'Gap'}</span>
                   </div>
-                  
+
                   <div className="rs-metric" style={{ width: '40px' }}>
                     <span style={{ color: Number(currentPoints) > 0 ? 'var(--text)' : 'var(--text-3)' }}>
                       {currentPoints}

frontend/src/components/ReplayTrackMap.tsx

@@ -0,0 +1,159 @@
+import { useMemo, useState } from 'react'
+import { Loader2, MapPin, Satellite } from 'lucide-react'
+import type { Driver, EnrichedResult, ReplayFramesResponse, TrackOutline } from '../types'
+import { buildOutlinePath } from '../lib/trackmap'
+import { interpolateReplayCars, replayCarToSvg } from '../lib/replay'
+import { EmptyStateCard } from './EmptyStateCard'
+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">
+        <EmptyStateCard
+          icon={Loader2}
+          title="Loading replay map"
+          hint="Fetching track outline and historical GPS frames."
+          testId="replay-map-loading"
+          className="replay-map-empty-card"
+        />
+      </section>
+    )
+  }
+
+  if (error) {
+    return (
+      <section className="replay-map-panel" data-testid="replay-track-map">
+        <EmptyStateCard
+          icon={Satellite}
+          title="Replay GPS unavailable"
+          hint="This session does not have ingested location samples for the replay map."
+          testId="replay-map-error"
+          className="replay-map-empty-card"
+        />
+      </section>
+    )
+  }
+
+  if (!outline || !outlinePath) {
+    return (
+      <section className="replay-map-panel" data-testid="replay-track-map">
+        <EmptyStateCard
+          icon={MapPin}
+          title="Track outline unavailable"
+          hint="Circuit GPS outline data is missing for this session."
+          testId="replay-map-no-outline"
+          className="replay-map-empty-card"
+        />
+      </section>
+    )
+  }
+
+  if (!replay?.frames?.length || cars.length === 0) {
+    return (
+      <section className="replay-map-panel" data-testid="replay-track-map">
+        <EmptyStateCard
+          icon={Satellite}
+          title="Historical GPS unavailable"
+          hint="Fewer than two replay frames were returned for this session."
+          testId="replay-map-no-frames"
+          className="replay-map-empty-card"
+        />
+      </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/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/components/live/RaceControlFeed.tsx

@@ -80,7 +80,9 @@ export function RaceControlFeed({ messages, driverInfo }: Props) {
     <section className="live-rc panel-glass">
       <div className="sec-header sticky-header">
         <span className="sec-title">Race Control</span>
-        {messages.length > 0 && <span className="sec-meta">{messages.length} messages</span>}
+        <span className="sec-meta" data-testid="rc-timezone">
+          {messages.length > 0 ? `${messages.length} messages · ` : ''}times UTC
+        </span>
       </div>
       {latest.length === 0 ? (
         <div className="missing-notice">No race control messages in the current live snapshot.</div>
@@ -102,7 +104,7 @@ export function RaceControlFeed({ messages, driverInfo }: Props) {
 
             return (
               <div className={`live-rc-row${flashClass}`} key={key}>
-                <span className="rc-time">{message.Time || '--:--'}</span>
+                <span className="rc-time" title="UTC">{message.Time || '--:--'}</span>
                 {message.Lap > 0 && <span className="rc-lap">L{message.Lap}</span>}
                 {message.Flag
                   ? <span className={`rc-flag ${rcFlagClass(message.Flag)}`}>{message.Flag}</span>

frontend/src/components/live/SessionBanner.tsx

@@ -38,9 +38,11 @@ export function SessionBanner({ isLive, isArchive = false, snapshot, rows, conne
           <div className="live-banner-meta">
             {display.advanceCount && <span>{display.advanceCount} advance</span>}
             {atRiskLabel && <span>{atRiskLabel}</span>}
-            <span>
-              L<strong>{snapshot.CurrentLap || '-'}</strong>/<strong>{snapshot.TotalLaps || '-'}</strong>
-            </span>
+            {display.isRace && (
+              <span data-testid="live-lap-counter">
+                L<strong>{snapshot.CurrentLap || '-'}</strong>/<strong>{snapshot.TotalLaps || '-'}</strong>
+              </span>
+            )}
             <span className={isLive ? 'live-state live-state-on' : 'live-state'}>{stateLabel}</span>
           </div>
         </div>

frontend/src/components/live/TimingTower.tsx

@@ -1,9 +1,10 @@
-import { useState, Fragment } from 'react'
+import { useState, useMemo, Fragment } from 'react'
 import { teamColor } from '../../utils'
 import { useAutoAnimate } from '@formkit/auto-animate/react'
 import type { LiveSessionMeta, LiveStintData } from '../../types'
 import type { LiveTimingRow } from '../../lib/live'
 import {
+  bestLapGaps,
   driverCode,
   liveSessionDisplay,
   positionDelta,
@@ -62,6 +63,10 @@ export function TimingTower({
   const isQuali = sessionDisplay.isQualifying || !isRace
   const columnCount = 7 + (isRace ? 3 : 0) + (isQuali ? 3 : 0)
 
+  // Practice/qualifying: derive a display-only gap to P1 from valid best laps
+  // when the upstream feed omits GapToLeader. Empty for races (feed is truth).
+  const practiceGaps = useMemo(() => bestLapGaps(isRace ? [] : rows), [isRace, rows])
+
   return (
     <div className="scroll-x">
       <table className="data-table live-tower" style={{ minWidth: 760 }}>
@@ -71,9 +76,9 @@ export function TimingTower({
             {isRace && <th>Δ</th>}
             <th>Driver</th>
             <th>Tyre</th>
-            <th>Last Lap</th>
-            <th 
-              className="interactive" 
+            <th className={isRace ? undefined : 'hide-mobile'}>Last Lap</th>
+            <th
+              className="interactive"
               onClick={() => setGapMode(g => g === 'interval' ? 'leader' : 'interval')}
               title="Click to toggle Gap vs Interval"
               style={{ cursor: 'pointer', textDecoration: 'underline' }}
@@ -81,10 +86,10 @@ export function TimingTower({
               {gapMode === 'interval' && isRace ? 'Interval' : 'Gap to P1'}
             </th>
             {isRace && <th>Trend</th>}
-            {isQuali && <th>S1</th>}
-            {isQuali && <th>S2</th>}
-            {isQuali && <th>S3</th>}
-            <th className="hide-mobile">Best</th>
+            {isQuali && <th className="hide-mobile">S1</th>}
+            {isQuali && <th className="hide-mobile">S2</th>}
+            {isQuali && <th className="hide-mobile">S3</th>}
+            <th className={isRace ? 'hide-mobile' : undefined}>Best</th>
             {isRace && <th className="hide-mobile r">Laps</th>}
             <th className="r"></th>
           </tr>
@@ -102,7 +107,15 @@ export function TimingTower({
               driver.Cutoff
             const showCutoffAfter = row.Position === sessionDisplay.cutoffPosition
 
-            const gapText = gapMode === 'interval' && isRace ? (driver.Interval || driver.GapToLeader) : driver.GapToLeader
+            let gapText: string
+            if (isRace) {
+              gapText = gapMode === 'interval' ? (driver.Interval || driver.GapToLeader) : driver.GapToLeader
+            } else if (driver.GapToLeader) {
+              gapText = driver.GapToLeader
+            } else {
+              const computed = practiceGaps[row.RacingNumber]
+              gapText = computed ? (computed.isLeader ? '—' : computed.gap) : ''
+            }
             const intervalAnnotation =
               gapMode === 'interval' && isRace && row.Position > 1
                 ? intervalMeaning(parseIntervalSeconds(gapText))
@@ -153,7 +166,10 @@ export function TimingTower({
                   <td>
                     <span className={`tyre-badge ${tyreClass(row.Tyre)}`}>{tyreLabel(row.Tyre)}</span>
                   </td>
-                  <td className={driver.LastLapOB ? 'mono lap-ob' : driver.LastLapPB ? 'mono lap-pb' : 'mono'}>
+                  <td className={[
+                    isRace ? '' : 'hide-mobile',
+                    driver.LastLapOB ? 'mono lap-ob' : driver.LastLapPB ? 'mono lap-pb' : 'mono',
+                  ].filter(Boolean).join(' ')}>
                     {driver.LastLapTime || '-'}
                   </td>
                   <td className="mono">
@@ -171,11 +187,14 @@ export function TimingTower({
                     </td>
                   )}
 
-                  {isQuali && <td>{renderSector(0)}</td>}
-                  {isQuali && <td>{renderSector(1)}</td>}
-                  {isQuali && <td>{renderSector(2)}</td>}
+                  {isQuali && <td className="hide-mobile">{renderSector(0)}</td>}
+                  {isQuali && <td className="hide-mobile">{renderSector(1)}</td>}
+                  {isQuali && <td className="hide-mobile">{renderSector(2)}</td>}
 
-                  <td className={`hide-mobile ${driver.BestLapOB ? 'mono lap-ob' : 'mono'}`}>
+                  <td className={[
+                    isRace ? 'hide-mobile' : '',
+                    driver.BestLapOB ? 'mono lap-ob' : 'mono',
+                  ].filter(Boolean).join(' ')}>
                     {driver.BestLapTime || '-'}
                   </td>
                   
@@ -208,6 +227,16 @@ export function TimingTower({
                                  <div className="mono">{driver.NumberOfLaps || 0}</div>
                               </div>
                             )}
+                            {!isRace && driver.Sectors?.some((sec) => sec?.Value) && (
+                              <div data-testid="expanded-sectors">
+                                 <div className="mono" style={{ color: 'var(--text-3)', fontSize: '10px', marginBottom: '4px' }}>SECTORS</div>
+                                 <div className="mono" style={{ display: 'flex', gap: '10px' }}>
+                                    {renderSector(0)}
+                                    {renderSector(1)}
+                                    {renderSector(2)}
+                                 </div>
+                              </div>
+                            )}
                             {driver.SpeedTrap && (
                               <div>
                                  <div className="mono" style={{ color: 'var(--text-3)', fontSize: '10px', marginBottom: '4px' }}>SPEED TRAP</div>

frontend/src/components/live/TyreDegPanel.tsx

@@ -52,7 +52,10 @@ function StintSparkline({ seconds }: { seconds: number[] }) {
 }
 
 export function TyreDegPanel({ rows, sessionType, pinned }: Props) {
-  const [collapsed, setCollapsed] = useState(false)
+  const isRace = isRaceSession(sessionType)
+  // In practice/qualifying deg trends are secondary — collapse by default so
+  // the Timing Tower stays above the fold. Races keep it open.
+  const [collapsed, setCollapsed] = useState(!isRace)
   const [stints, setStints] = useState<StintHistoryMap>({})
 
   // One lap-history update per received snapshot (rows is rebuilt per snapshot).
@@ -61,8 +64,6 @@ export function TyreDegPanel({ rows, sessionType, pinned }: Props) {
     setStints((prev) => recordStintSamples(prev, rows.map(stintInputFromRow)))
   }, [rows])
 
-  const isRace = isRaceSession(sessionType)
-
   const visible = useMemo(
     () =>
       rows.filter(

frontend/src/lib/chapters.ts

@@ -0,0 +1,132 @@
+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.
+ * Uses the same 0–1 clamped bounds as chapterStartScrub/chapterEndScrub so
+ * chapters whose timestamps fall outside the position-sample window still
+ * activate when the scrubber is parked at the clamped edge. */
+export function activeChapterIndex(
+  chapters: Chapter[],
+  scrubTime: number | null,
+  tMin: number,
+  tRange: number,
+): number | null {
+  if (scrubTime === null || chapters.length === 0 || tRange <= 0) return null
+  for (let i = 0; i < chapters.length; i++) {
+    const start = chapterStartScrub(chapters[i], tMin, tRange)
+    const end = chapterEndScrub(chapters[i], tMin, tRange)
+    if (start === null || end === null) continue
+    const lo = Math.min(start, end)
+    const hi = Math.max(start, end)
+    if (scrubTime >= lo && scrubTime <= hi) 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)
+}
+
+/** Decimated position axis labels, e.g. P1, P5, P10, P15, P20. */
+export function decimatedPositionLabels(maxPos: number): number[] {
+  if (maxPos <= 1) return [1]
+  const labels = new Set<number>([1])
+  for (let pos = 5; pos < maxPos; pos += 5) {
+    labels.add(pos)
+  }
+  labels.add(maxPos)
+  return [...labels].sort((a, b) => a - b)
+}
+
+/** Subtle background fill for chapter time-bands on the position graph. */
+export function chapterBandFill(kind: string): string {
+  switch (kind) {
+    case 'safety_car':
+      return 'rgba(255, 153, 0, 0.14)'
+    case 'virtual_safety_car':
+      return 'rgba(255, 204, 0, 0.12)'
+    case 'red_flag':
+      return 'rgba(230, 36, 41, 0.12)'
+    case 'pit_phase':
+      return 'rgba(96, 165, 250, 0.08)'
+    case 'decisive_swing':
+      return 'rgba(34, 197, 94, 0.08)'
+    case 'finish':
+      return 'rgba(255, 204, 0, 0.06)'
+    default:
+      return 'rgba(255, 255, 255, 0.03)'
+  }
+}
+
+/** Minimum vertical spacing between colliding labels (SVG units). */
+export function deCollideYPositions(
+  items: ReadonlyArray<{ key: string | number; y: number }>,
+  minGap = 12,
+): Map<string | number, number> {
+  if (items.length === 0) return new Map()
+  const sorted = [...items].sort((a, b) => a.y - b.y)
+  const adjusted = sorted.map((item) => ({ ...item }))
+  for (let i = 1; i < adjusted.length; i++) {
+    const prev = adjusted[i - 1]
+    const curr = adjusted[i]
+    if (curr.y - prev.y < minGap) {
+      curr.y = prev.y + minGap
+    }
+  }
+  return new Map(adjusted.map((item) => [item.key, item.y]))
+}

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/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/live.ts

@@ -268,6 +268,63 @@ export function driverCode(row: LiveTimingRow): string {
   return row.Info?.Tla || row.RacingNumber
 }
 
+/**
+ * Parse an F1 lap-time string ("1:45.944", "45.944") into total seconds.
+ * Returns null for empty/invalid values so callers never invent a gap.
+ */
+export function parseLapTimeSeconds(value: string | null | undefined): number | null {
+  if (!value) return null
+  const match = value.trim().match(/^(?:(\d+):)?([0-5]?\d(?:\.\d+)?)$/)
+  if (!match) return null
+  const minutes = match[1] ? Number(match[1]) : 0
+  const seconds = Number(match[2])
+  if (!Number.isFinite(minutes) || !Number.isFinite(seconds)) return null
+  return minutes * 60 + seconds
+}
+
+export interface BestLapGap {
+  isLeader: boolean
+  gap: string
+}
+
+/**
+ * Display-only gap-to-P1 for practice/qualifying, derived from each driver's
+ * valid best lap. Only drivers with a parseable best lap get an entry, and the
+ * fastest is flagged as the leader. Never fabricates a gap from a missing or
+ * invalid lap — the upstream interval remains the source of truth for races.
+ */
+export function bestLapGaps(rows: ReadonlyArray<LiveTimingRow>): Record<string, BestLapGap> {
+  let leaderNumber = ''
+  let best = Infinity
+  for (const row of rows) {
+    const seconds = parseLapTimeSeconds(row.Driver.BestLapTime)
+    if (seconds === null) continue
+    if (seconds < best) {
+      best = seconds
+      leaderNumber = row.RacingNumber
+    }
+  }
+
+  const out: Record<string, BestLapGap> = {}
+  if (!Number.isFinite(best)) return out
+  for (const row of rows) {
+    const seconds = parseLapTimeSeconds(row.Driver.BestLapTime)
+    if (seconds === null) continue
+    out[row.RacingNumber] =
+      row.RacingNumber === leaderNumber
+        ? { isLeader: true, gap: '' }
+        : { isLeader: false, gap: `+${(seconds - best).toFixed(3)}` }
+  }
+  return out
+}
+
+/** True when the live feed reports an in-progress session with timing data. */
+export function isLiveSessionActive(
+  state: { is_live?: boolean; data?: unknown } | null | undefined,
+): boolean {
+  return Boolean(state?.is_live && state.data)
+}
+
 export function trackStatusLabel(status: string): string {
   return TRACK_STATUS_LABELS[status] || status || 'UNKNOWN'
 }

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/replayMap.ts

@@ -0,0 +1,14 @@
+import type { ReplayFramesResponse, TrackOutline } from '../types'
+
+/** Whether replay map can render (probe uses existing frames + outline queries). */
+export function isReplayMapAvailable(
+  replay: ReplayFramesResponse | null | undefined,
+  outline: TrackOutline | null | undefined,
+  hasError: boolean,
+): boolean {
+  if (hasError) return false
+  const frames = replay?.frames ?? []
+  if (frames.length < 2) return false
+  if (!outline?.points?.length) return false
+  return true
+}

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

@@ -7,6 +7,8 @@ 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' | 'rivalry' | 'simulator'
@@ -252,6 +254,7 @@ function ChampionshipBody({ hub, view, setView }: BodyProps) {
           leaderPoints={leader.points}
           titleMath={titleMath}
           roundsLeft={hub.rounds_left}
+          drivers={drivers}
           season={hub.season}
         />
       )}
@@ -283,15 +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">
@@ -350,6 +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>

frontend/src/styles/app.css

@@ -112,6 +112,30 @@ a { color: inherit; text-decoration: none; }
 .nav-links a:hover { color: var(--text); background: var(--surface-h); }
 .nav-links a.active { color: var(--text); background: var(--surface-2); }
 
+/* Live nav gets a pulsing marker only while a session is on air. */
+.nav-live { display: inline-flex; align-items: center; gap: 6px; }
+.nav-links a.nav-live-on { color: var(--text); font-weight: 600; }
+.nav-live-dot {
+  width: 7px;
+  height: 7px;
+  border-radius: 50%;
+  background: var(--red);
+  box-shadow: 0 0 0 0 rgba(225, 6, 0, 0.4);
+  animation: pulse-live 1.6s infinite;
+}
+
+.sr-only {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  padding: 0;
+  margin: -1px;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+}
+
 .nav-utility {
   margin-left: auto;
   display: flex;

frontend/src/styles/chapters.css

@@ -0,0 +1,208 @@
+.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);
+  flex-wrap: wrap;
+}
+
+.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-wrap {
+  position: relative;
+}
+
+.chapter-strip-scroll-wrap::before,
+.chapter-strip-scroll-wrap::after {
+  content: '';
+  position: absolute;
+  top: 0;
+  bottom: var(--s2);
+  width: 28px;
+  pointer-events: none;
+  z-index: 1;
+}
+
+.chapter-strip-scroll-wrap::before {
+  left: 0;
+  background: linear-gradient(to right, var(--bg), transparent);
+}
+
+.chapter-strip-scroll-wrap::after {
+  right: 0;
+  background: linear-gradient(to left, var(--bg), transparent);
+}
+
+.chapter-strip-scroll {
+  display: flex;
+  gap: var(--s3);
+  overflow-x: auto;
+  padding-bottom: var(--s2);
+  scroll-snap-type: x mandatory;
+  -webkit-overflow-scrolling: touch;
+  scrollbar-width: thin;
+  scrollbar-color: var(--border-2) transparent;
+}
+
+.chapter-strip-scroll::-webkit-scrollbar {
+  height: 4px;
+}
+
+.chapter-strip-scroll::-webkit-scrollbar-track {
+  background: transparent;
+}
+
+.chapter-strip-scroll::-webkit-scrollbar-thumb {
+  background: var(--border-2);
+  border-radius: 999px;
+}
+
+.chapter-card {
+  flex: 0 0 min(240px, 72vw);
+  min-height: 88px;
+  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: center;
+  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;
+  flex: 1;
+}
+
+.chapter-strip-empty-card {
+  padding: var(--s6) var(--s5);
+  margin: 0;
+}
+
+.chapter-strip-empty-card .empty-state-icon {
+  display: block;
+  margin: 0 auto var(--s3);
+  color: var(--text-3);
+}
+
+@media (max-width: 900px) {
+  .chapter-strip-header {
+    align-items: flex-start;
+  }
+}

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/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/race-story.css

@@ -0,0 +1,157 @@
+.race-story-empty-card {
+  padding: var(--s6) var(--s5);
+  margin: 0;
+}
+
+.race-story-empty-card .empty-state-icon {
+  display: block;
+  margin: 0 auto var(--s3);
+  color: var(--text-3);
+}
+
+.rs-replay-shell {
+  display: grid;
+  grid-template-columns: 1fr;
+  gap: var(--s5);
+  align-items: stretch;
+}
+
+.rs-replay-shell--split {
+  grid-template-columns: minmax(0, 1.4fr) minmax(260px, 0.8fr);
+}
+
+.rs-replay-main {
+  min-width: 0;
+}
+
+.rs-chart-container {
+  --rs-chart-max-width: 100%;
+}
+
+.rs-chart-container--full {
+  --rs-chart-max-width: 100%;
+}
+
+.rs-segmented-control {
+  display: inline-flex;
+  align-items: stretch;
+  flex-wrap: wrap;
+  gap: 0;
+  margin-top: var(--s3);
+  border: 1px solid var(--border-2);
+  border-radius: var(--s1);
+  background: var(--surface);
+  overflow: hidden;
+}
+
+.rs-segment {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  min-height: 30px;
+  padding: 0 var(--s4);
+  font-family: var(--f-mono);
+  font-size: 10px;
+  font-weight: 700;
+  letter-spacing: 0.04em;
+  color: var(--text-3);
+  background: transparent;
+  border: none;
+  border-right: 1px solid var(--border);
+  cursor: pointer;
+  transition: background 0.12s, color 0.12s;
+}
+
+.rs-segment:last-child {
+  border-right: none;
+}
+
+.rs-segment:hover:not(:disabled) {
+  color: var(--text);
+  background: var(--surface-h);
+}
+
+.rs-segment:focus-visible {
+  outline: 2px solid var(--red);
+  outline-offset: -2px;
+  z-index: 1;
+}
+
+.rs-segment.active {
+  color: var(--text);
+  background: rgba(230, 36, 41, 0.12);
+  box-shadow: inset 0 -2px 0 var(--red);
+}
+
+.rs-segment:disabled {
+  opacity: 0.45;
+  cursor: not-allowed;
+}
+
+.rs-segment-divider {
+  width: 1px;
+  align-self: stretch;
+  background: var(--border);
+  flex-shrink: 0;
+}
+
+.rs-replay-map-slot {
+  min-width: 0;
+}
+
+.rs-position-chart-svg {
+  width: 100%;
+  min-width: 280px;
+  max-width: var(--rs-chart-max-width, 640px);
+  display: block;
+}
+
+.rs-chart-axis-label {
+  fill: var(--text-3);
+  font-family: var(--f-mono);
+  font-size: 9px;
+}
+
+.rs-chart-grid-line {
+  stroke: var(--border);
+  stroke-width: 0.5;
+}
+
+.rs-chart-lap-tick {
+  stroke: var(--border);
+  stroke-width: 1;
+}
+
+@media (max-width: 900px) {
+  .rs-replay-shell--split {
+    grid-template-columns: 1fr;
+  }
+
+  .rs-segmented-control {
+    width: 100%;
+  }
+
+  .rs-segment {
+    flex: 1 1 auto;
+  }
+}
+
+@media (max-width: 560px) {
+  .rs-segmented-control {
+    flex-direction: column;
+    align-items: stretch;
+  }
+
+  .rs-segment {
+    border-right: none;
+    border-bottom: 1px solid var(--border);
+  }
+
+  .rs-segment:last-child {
+    border-bottom: none;
+  }
+
+  .rs-segment-divider {
+    display: none;
+  }
+}

frontend/src/styles/replay-map.css

@@ -0,0 +1,91 @@
+.replay-map-panel {
+  min-height: 244px;
+  height: 100%;
+  border: 1px solid var(--border);
+  background: var(--surface);
+  border-radius: var(--s2);
+}
+
+.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-card {
+  min-height: 244px;
+  display: grid;
+  place-content: center;
+  padding: var(--s6);
+  margin: 0;
+}
+
+.replay-map-empty-card .empty-state-icon {
+  display: block;
+  margin: 0 auto var(--s3);
+  color: var(--text-3);
+}

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

@@ -169,4 +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/ChapterStrip.test.tsx

@@ -0,0 +1,128 @@
+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('renders an empty-state card when there are no chapters', () => {
+    const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+    render(
+      <QueryClientProvider client={queryClient}>
+        <ChapterStrip
+          chapters={[]}
+          scrubTime={null}
+          tMin={tMin}
+          tRange={tRange}
+          tourActive={false}
+          tourChapterIndex={null}
+          onChapterClick={vi.fn()}
+          onTourToggle={vi.fn()}
+        />
+      </QueryClientProvider>,
+    )
+    expect(screen.getByTestId('chapter-strip-empty')).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)
+  })
+
+  it('highlights an explicitly selected chapter even when scrub is outside its raw window', () => {
+    // Scrub parked at chart start; chapter 1's raw times are mid-race, but selection wins.
+    const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+    render(
+      <QueryClientProvider client={queryClient}>
+        <ChapterStrip
+          chapters={chapters}
+          scrubTime={0}
+          tMin={tMin}
+          tRange={tRange}
+          tourActive={false}
+          tourChapterIndex={null}
+          selectedChapterIndex={1}
+          onChapterClick={vi.fn()}
+          onTourToggle={vi.fn()}
+        />
+      </QueryClientProvider>,
+    )
+    expect(screen.getByTestId('chapter-card-1')).toHaveClass('active')
+    expect(screen.getByTestId('chapter-card-0')).not.toHaveClass('active')
+  })
+})

frontend/src/test/LiveComponents.test.tsx

@@ -209,6 +209,32 @@ describe('TimingTower', () => {
     expect(screen.getByText('DRS range')).toBeInTheDocument()
   })
 
+  it('derives a gap to P1 from best laps when the practice feed omits GapToLeader', () => {
+    const practiceRows = [
+      makeRow('1', 1, 'VER', { BestLapTime: '1:45.944', GapToLeader: '' }),
+      makeRow('4', 2, 'NOR', { BestLapTime: '1:46.134', GapToLeader: '' }),
+      makeRow('16', 3, 'LEC', { BestLapTime: '', GapToLeader: '' }),
+    ]
+    render(
+      <TimingTower
+        rows={practiceRows}
+        session={{
+          MeetingName: 'Belgian Grand Prix',
+          CircuitName: 'Spa',
+          SessionType: 'Practice',
+          SessionName: 'Practice 2',
+          Path: '',
+        }}
+      />,
+    )
+    // Leader shows a clear leader marker, not a fabricated gap.
+    expect(screen.getByText('VER').closest('tr')).toHaveTextContent('—')
+    expect(screen.getByText('+0.190')).toBeInTheDocument()
+    // A driver without a valid best lap gets no invented gap.
+    const lecRow = screen.getByText('LEC').closest('tr')!
+    expect(lecRow).not.toHaveTextContent('+')
+  })
+
   it('renders the SQ1 cutoff after P17 and marks rows below as at risk', () => {
     const sprintRows = Array.from({ length: 22 }, (_, index) =>
       makeRow(String(index + 1), index + 1, `D${index + 1}`),

frontend/src/test/LiveTimingPage.test.tsx

@@ -153,6 +153,29 @@ describe('LiveTimingPage archive mode', () => {
     expect(screen.queryByRole('button', { name: /view last session/i })).not.toBeInTheDocument()
   })
 
+  it('renders the live session for a red-flag paused snapshot instead of the inactive empty state', async () => {
+    renderPage({
+      is_live: true,
+      data: {
+        ...archivedSnapshot,
+        SessionStatus: 'Inactive',
+        TrackStatus: '2',
+        Clock: '00:03:27',
+        Session: {
+          MeetingName: 'Belgian Grand Prix',
+          CircuitName: 'Spa-Francorchamps',
+          SessionType: 'Practice',
+          SessionName: 'Practice 2',
+          Path: '',
+        },
+      },
+    })
+
+    expect(await screen.findByText('Timing Tower')).toBeInTheDocument()
+    expect(screen.queryByTestId('live-empty')).not.toBeInTheDocument()
+    expect(screen.queryByTestId('live-archive-strip')).not.toBeInTheDocument()
+  })
+
   it('temporarily omits the track map while live GPS is unavailable', async () => {
     renderPage({
       is_live: true,

frontend/src/test/RaceStoryCanvas.test.tsx

@@ -0,0 +1,291 @@
+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 { Chapter, 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 } } },
+    { t: 5000, cars: { '1': { x: 50, y: 50 } } },
+  ],
+}
+
+const chapters: Chapter[] = [
+  {
+    kind: 'start',
+    title: 'Start',
+    headline: 'Lights out',
+    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',
+    headline: 'Incident brings out the Safety Car',
+    start_lap: 2,
+    end_lap: 2,
+    start_time: '2025-05-25T13:05:00Z',
+    end_time: '2025-05-25T13:05:00Z',
+    driver_numbers: [],
+  },
+]
+
+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(overrides: Partial<RaceHub> = {}) {
+  const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } })
+  return render(
+    <QueryClientProvider client={queryClient}>
+      <RaceStoryCanvas data={{ ...raceHub, ...overrides }} />
+    </QueryClientProvider>,
+  )
+}
+
+describe('RaceStoryCanvas replay map', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockFetchReplayFrames.mockResolvedValue(replay)
+    mockFetchTrackOutline.mockResolvedValue(outline)
+  })
+
+  it('probes replay frames on mount and opens the map when data is available', async () => {
+    renderCanvas()
+
+    await waitFor(() => expect(mockFetchReplayFrames).toHaveBeenCalledWith(99, 5000))
+    expect(mockFetchTrackOutline).toHaveBeenCalledWith(1, 2025)
+
+    const mapToggle = await screen.findByTestId('replay-map-toggle')
+    fireEvent.click(mapToggle)
+
+    expect(await screen.findByTestId('replay-track-map')).toBeInTheDocument()
+    expect(screen.getByTestId('replay-map-slot')).toBeInTheDocument()
+  })
+
+  it('hides the map toggle when replay frames are unavailable', async () => {
+    mockFetchReplayFrames.mockResolvedValue({ ...replay, frames: [] })
+    renderCanvas()
+
+    await waitFor(() => expect(mockFetchReplayFrames).toHaveBeenCalled())
+    await waitFor(() => expect(screen.queryByTestId('replay-map-toggle')).not.toBeInTheDocument())
+  })
+
+  it('uses full-width chart layout when the map is closed', async () => {
+    renderCanvas()
+
+    await waitFor(() => expect(mockFetchReplayFrames).toHaveBeenCalled())
+    const chart = screen.getByTestId('position-chart')
+    expect(chart).toHaveClass('rs-chart-container--full')
+    expect(screen.queryByTestId('replay-map-slot')).not.toBeInTheDocument()
+    expect(document.querySelector('.rs-replay-shell--split')).not.toBeInTheDocument()
+  })
+
+  it('uses lap timing rather than pre-race position samples for the chart scale', () => {
+    const laps = Array.from({ length: 20 }, (_, index) => ({
+      session_key: 99,
+      driver_number: 1,
+      meeting_key: 1,
+      lap_number: index + 1,
+      date_start: `2025-05-25T13:${String(index).padStart(2, '0')}:00Z`,
+      lap_duration: 60,
+      is_pit_out_lap: false,
+    }))
+
+    renderCanvas({
+      results: [{ ...raceHub.results[0], number_of_laps: 20 }],
+      laps,
+      positions: [
+        { session_key: 99, driver_number: 1, meeting_key: 1, date: '2025-05-25T12:00:00Z', position: 1 },
+        { session_key: 99, driver_number: 1, meeting_key: 1, date: '2025-05-25T13:20:00Z', position: 1 },
+      ],
+    })
+
+    // L10 is the end of the tenth 60s lap, exactly halfway through the race.
+    const lapTenLabel = screen.getByText('L10')
+    expect(lapTenLabel.previousElementSibling).toHaveAttribute('x1', '316')
+    // The pre-race position is retained as the starting grid at the left edge.
+    expect(document.querySelector('.rs-driver-line')).toHaveAttribute('points', '40,8 592,8 592,8')
+  })
+
+  it('maps cursor positions from rendered pixels to the SVG viewBox', () => {
+    renderCanvas()
+
+    const svg = document.querySelector('.rs-position-chart-svg')!
+    vi.spyOn(svg, 'getBoundingClientRect').mockReturnValue({
+      x: 0,
+      y: 0,
+      width: 1280,
+      height: 360,
+      top: 0,
+      right: 1280,
+      bottom: 360,
+      left: 0,
+      toJSON: () => ({}),
+    })
+
+    const pointerMove = new Event('pointermove', { bubbles: true })
+    Object.defineProperty(pointerMove, 'clientX', { value: 640 })
+    fireEvent(screen.getByTestId('position-chart-interaction'), pointerMove)
+
+    // 640px is the middle of a 1280px rendered chart, which is x=320 in its 640-unit viewBox.
+    expect(document.querySelector('.rs-playhead')).toHaveAttribute('x1', '320')
+  })
+
+  it('syncs active chapter highlight when a chapter card is clicked', async () => {
+    renderCanvas()
+
+    fireEvent.click(screen.getByTestId('chapter-card-1'))
+    await waitFor(() => expect(screen.getByTestId('chapter-card-1')).toHaveClass('active'))
+    expect(screen.getByTestId('chapter-card-0')).not.toHaveClass('active')
+  })
+
+  it('highlights out-of-window chapters after click (clamped scrub + selection)', async () => {
+    // Position samples start at 13:05; start chapter ends at 13:01 — outside the window.
+    renderCanvas({
+      positions: [
+        { session_key: 99, driver_number: 1, meeting_key: 1, date: '2025-05-25T13:05:00Z', position: 1 },
+        { session_key: 99, driver_number: 1, meeting_key: 1, date: '2025-05-25T13:10:00Z', position: 1 },
+      ],
+      chapters: [
+        {
+          kind: 'start',
+          title: 'Start',
+          headline: 'Lights out before samples',
+          start_lap: 1,
+          end_lap: 1,
+          start_time: '2025-05-25T13:00:00Z',
+          end_time: '2025-05-25T13:01:00Z',
+          driver_numbers: [],
+        },
+        {
+          kind: 'finish',
+          title: 'Finish',
+          headline: 'Flag after samples',
+          start_lap: 78,
+          end_lap: 78,
+          start_time: '2025-05-25T13:20:00Z',
+          end_time: '2025-05-25T13:21:00Z',
+          driver_numbers: [],
+        },
+      ],
+    })
+
+    fireEvent.click(screen.getByTestId('chapter-card-0'))
+    await waitFor(() => expect(screen.getByTestId('chapter-card-0')).toHaveClass('active'))
+    expect(screen.getByTestId('chapter-card-1')).not.toHaveClass('active')
+
+    fireEvent.click(screen.getByTestId('chapter-card-1'))
+    await waitFor(() => expect(screen.getByTestId('chapter-card-1')).toHaveClass('active'))
+    expect(screen.getByTestId('chapter-card-0')).not.toHaveClass('active')
+  })
+
+  it('renders the empty-state card when positions are unavailable', () => {
+    renderCanvas({
+      datasets: { positions: { status: 'missing', source: 'local', count: 0 } },
+      positions: [],
+      chapters: [],
+    })
+
+    expect(screen.getByTestId('race-story-no-positions')).toBeInTheDocument()
+    expect(screen.getByText('Lap-by-lap positions not available')).toBeInTheDocument()
+  })
+})

frontend/src/test/ReplayTrackMap.test.tsx

@@ -0,0 +1,57 @@
+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 card when replay frames are missing', () => {
+    render(<ReplayTrackMap outline={outline} replay={{ ...replay, frames: [] }} tMs={0} drivers={[]} results={results} />)
+    expect(screen.getByTestId('replay-map-no-frames')).toBeInTheDocument()
+    expect(screen.getByText('Historical GPS unavailable')).toBeInTheDocument()
+  })
+
+  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/SessionBanner.test.tsx

@@ -0,0 +1,61 @@
+import { describe, expect, it } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import { SessionBanner } from '../components/live/SessionBanner'
+import type { LiveStreamData } from '../types'
+
+function makeSnapshot(sessionType: string, sessionName: string): LiveStreamData {
+  return {
+    Drivers: {},
+    DriverInfo: {},
+    Tyres: {},
+    RCMessages: [],
+    Weather: { AirTemp: 0, TrackTemp: 0, Humidity: 0, WindSpeed: 0, WindDir: 0, Rainfall: false },
+    Session: {
+      MeetingName: 'Belgian Grand Prix',
+      CircuitName: 'Spa-Francorchamps',
+      SessionType: sessionType,
+      SessionName: sessionName,
+      Path: '',
+    },
+    TeamRadio: [],
+    TrackStatus: '1',
+    CurrentLap: 0,
+    TotalLaps: 0,
+    Clock: '00:45:00',
+    ClockRefTime: '',
+    ClockExtrapolating: false,
+    Stints: {},
+  }
+}
+
+describe('SessionBanner', () => {
+  it('never renders a race lap counter for a practice session', () => {
+    render(
+      <SessionBanner
+        isLive
+        snapshot={makeSnapshot('Practice', 'Practice 2')}
+        rows={[]}
+        connection="connected"
+        now={0}
+      />,
+    )
+    expect(screen.queryByTestId('live-lap-counter')).not.toBeInTheDocument()
+    // Session identity and clock stay intact.
+    expect(screen.getByText('Belgian Grand Prix')).toBeInTheDocument()
+    expect(screen.getByTestId('live-clock')).toHaveTextContent('00:45:00')
+  })
+
+  it('shows the lap counter for a race session', () => {
+    const snapshot = { ...makeSnapshot('Race', 'Race'), CurrentLap: 12, TotalLaps: 44 }
+    render(
+      <SessionBanner
+        isLive
+        snapshot={snapshot}
+        rows={[]}
+        connection="connected"
+        now={0}
+      />,
+    )
+    expect(screen.getByTestId('live-lap-counter')).toHaveTextContent('L12/44')
+  })
+})

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/TyreDegPanel.test.tsx

@@ -81,14 +81,20 @@ describe('TyreDegPanel', () => {
     expect(panel).toHaveTextContent('→ ~P2')
   })
 
-  it('hides the rejoin estimate outside race sessions and collapses on toggle', () => {
+  it('collapses by default outside race sessions and hides the rejoin estimate when expanded', () => {
     render(<TyreDegPanel rows={snapshotRows(3, '1:30.000')} sessionType="Qualifying" pinned={[]} />)
     const panel = screen.getByTestId('tyredeg-panel')
-    expect(panel).not.toHaveTextContent('~P')
 
-    expect(screen.getAllByTestId('tyredeg-row')).toHaveLength(2)
-    fireEvent.click(screen.getByRole('button', { name: /tyre deg/i }))
+    // Practice/qualifying starts collapsed so the Timing Tower stays above the fold.
     expect(screen.queryAllByTestId('tyredeg-row')).toHaveLength(0)
+    fireEvent.click(screen.getByRole('button', { name: /tyre deg/i }))
+    expect(screen.getAllByTestId('tyredeg-row')).toHaveLength(2)
+    expect(panel).not.toHaveTextContent('~P')
+  })
+
+  it('starts expanded during a race', () => {
+    render(<TyreDegPanel rows={snapshotRows(3, '1:30.000')} sessionType="Race" pinned={[]} />)
+    expect(screen.getAllByTestId('tyredeg-row')).toHaveLength(2)
   })
 
   it('limits rows to the top ten plus pinned drivers', () => {

frontend/src/test/chapters.test.ts

@@ -0,0 +1,124 @@
+import { describe, expect, it } from 'vitest'
+import {
+  activeChapterIndex,
+  chapterBandFill,
+  chapterKindLabel,
+  chapterLapRange,
+  chapterStartScrub,
+  chapterTourDurations,
+  deCollideYPositions,
+  decimatedPositionLabels,
+} 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('activates chapters whose timestamps clamp outside the position window', () => {
+    // Position samples only cover 13:05–13:10; chapters sit before/after that window.
+    const tMin = new Date('2025-05-25T13:05:00Z').getTime()
+    const tMax = new Date('2025-05-25T13:10:00Z').getTime()
+    const tRange = tMax - tMin
+    const outOfWindow: Chapter[] = [
+      {
+        kind: 'start',
+        title: 'Start',
+        headline: 'Lights out',
+        start_lap: 1,
+        end_lap: 1,
+        start_time: '2025-05-25T13:00:00Z',
+        end_time: '2025-05-25T13:01:00Z',
+        driver_numbers: [],
+      },
+      {
+        kind: 'finish',
+        title: 'Finish',
+        headline: 'Chequered flag',
+        start_lap: 78,
+        end_lap: 78,
+        start_time: '2025-05-25T13:20:00Z',
+        end_time: '2025-05-25T13:21:00Z',
+        driver_numbers: [],
+      },
+    ]
+
+    expect(chapterStartScrub(outOfWindow[0], tMin, tRange)).toBe(0)
+    expect(chapterStartScrub(outOfWindow[1], tMin, tRange)).toBe(1)
+    expect(activeChapterIndex(outOfWindow, 0, tMin, tRange)).toBe(0)
+    expect(activeChapterIndex(outOfWindow, 1, tMin, tRange)).toBe(1)
+    expect(activeChapterIndex(outOfWindow, 0.5, tMin, tRange)).toBeNull()
+  })
+
+  it('splits 90s evenly across chapters', () => {
+    expect(chapterTourDurations(sampleChapters)).toEqual([45_000, 45_000])
+  })
+
+  it('decimates position axis labels', () => {
+    expect(decimatedPositionLabels(22)).toEqual([1, 5, 10, 15, 20, 22])
+  })
+
+  it('returns chapter band fills by kind', () => {
+    expect(chapterBandFill('safety_car')).toContain('rgba')
+    expect(chapterBandFill('virtual_safety_car')).toContain('rgba')
+  })
+
+  it('de-collides overlapping label y positions', () => {
+    const adjusted = deCollideYPositions(
+      [
+        { key: 'a', y: 10 },
+        { key: 'b', y: 12 },
+        { key: 'c', y: 30 },
+      ],
+      12,
+    )
+    expect(adjusted.get('a')).toBe(10)
+    expect(adjusted.get('b')).toBe(22)
+    expect(adjusted.get('c')).toBe(34)
+  })
+})

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/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/live.test.ts

@@ -1,12 +1,15 @@
 import { describe, expect, it } from 'vitest'
 import {
+  bestLapGaps,
   compoundClass,
   compoundLetter,
   extrapolateClock,
+  isLiveSessionActive,
   latestRaceControl,
   liveSessionDisplay,
   loadPinnedDrivers,
   mergeVisibleSectors,
+  parseLapTimeSeconds,
   positionDeltaClass,
   parseLiveStateEvent,
   rcFlagClass,
@@ -279,6 +282,43 @@ describe('live qualifying display', () => {
   })
 })
 
+describe('practice/qualifying computed gaps', () => {
+  it('parses lap-time strings into seconds and rejects invalid input', () => {
+    expect(parseLapTimeSeconds('1:45.944')).toBeCloseTo(105.944, 3)
+    expect(parseLapTimeSeconds('45.944')).toBeCloseTo(45.944, 3)
+    expect(parseLapTimeSeconds('')).toBeNull()
+    expect(parseLapTimeSeconds(undefined)).toBeNull()
+    expect(parseLapTimeSeconds('-')).toBeNull()
+    expect(parseLapTimeSeconds('nope')).toBeNull()
+  })
+
+  it('derives a gap to P1 from valid best laps only, flagging the leader', () => {
+    const gaps = bestLapGaps([
+      timingRow('1', 1, { BestLapTime: '1:45.944' }),
+      timingRow('4', 2, { BestLapTime: '1:46.134' }),
+      timingRow('16', 3, { BestLapTime: '' }),
+    ])
+    expect(gaps['1']).toEqual({ isLeader: true, gap: '' })
+    expect(gaps['4']).toEqual({ isLeader: false, gap: '+0.190' })
+    // No valid best lap → no fabricated gap.
+    expect(gaps['16']).toBeUndefined()
+  })
+
+  it('returns no gaps when nobody has set a lap', () => {
+    expect(bestLapGaps([timingRow('1', 1, { BestLapTime: '' })])).toEqual({})
+  })
+})
+
+describe('live session activity', () => {
+  it('is active only when the feed reports a live session with data', () => {
+    expect(isLiveSessionActive({ is_live: true, data: snapshot })).toBe(true)
+    expect(isLiveSessionActive({ is_live: true, data: null })).toBe(false)
+    expect(isLiveSessionActive({ is_live: false, data: snapshot })).toBe(false)
+    expect(isLiveSessionActive(null)).toBe(false)
+    expect(isLiveSessionActive(undefined)).toBe(false)
+  })
+})
+
 describe('visible sector display', () => {
   it('holds S1 and S2 through temporary blanks while a flying lap is active', () => {
     const first = [timingRow('4', 1, {

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/replayMap.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, it } from 'vitest'
+import { isReplayMapAvailable } from '../lib/replayMap'
+import type { ReplayFramesResponse, TrackOutline } from '../types'
+
+const outline: TrackOutline = {
+  circuit_key: 1,
+  bounds: { minX: 0, maxX: 100, minY: 0, maxY: 100 },
+  points: [{ x: 0, y: 0 }],
+}
+
+const replay: ReplayFramesResponse = {
+  session_key: 1,
+  interval_ms: 5000,
+  start_time: '2025-05-25T13:00:00Z',
+  frames: [
+    { t: 0, cars: {} },
+    { t: 5000, cars: {} },
+  ],
+}
+
+describe('isReplayMapAvailable', () => {
+  it('returns true when frames and outline are present', () => {
+    expect(isReplayMapAvailable(replay, outline, false)).toBe(true)
+  })
+
+  it('returns false when frames are sparse', () => {
+    expect(isReplayMapAvailable({ ...replay, frames: [{ t: 0, cars: {} }] }, outline, false)).toBe(false)
+  })
+
+  it('returns false on query error', () => {
+    expect(isReplayMapAvailable(replay, outline, true)).toBe(false)
+  })
+})

frontend/src/types.ts

@@ -97,6 +97,7 @@ export interface RaceHub {
 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
@@ -360,6 +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

internal/chapters/chapters.go

@@ -38,6 +38,7 @@ type Lap = models.Lap
 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"`

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/live/parser_test.go

@@ -307,6 +307,28 @@ func TestSessionStatusIsActive(t *testing.T) {
 	}
 }
 
+func TestSessionStatusIsTerminal(t *testing.T) {
+	tests := []struct {
+		status string
+		want   bool
+	}{
+		{"Finished", true},
+		{"Finalised", true},
+		{"Finalized", true},
+		{"Ends", true},
+		{"Aborted", true},
+		{"Started", false},
+		{"Resumed", false},
+		{"Inactive", false},
+		{"", false},
+	}
+	for _, tt := range tests {
+		if got := live.SessionStatusIsTerminal(tt.status); got != tt.want {
+			t.Errorf("SessionStatusIsTerminal(%q) = %v, want %v", tt.status, got, tt.want)
+		}
+	}
+}
+
 func TestProcessTopicRaceControlMessages(t *testing.T) {
 	state := live.NewState()
 	data := json.RawMessage(`{

internal/live/types.go

@@ -186,6 +186,19 @@ func SessionStatusIsActive(status string) bool {
 	}
 }
 
+// SessionStatusIsTerminal reports whether a raw F1 live timing SessionStatus
+// value represents a session that has ended and will not resume. A temporarily
+// inactive session (e.g. a red-flag pause reported as "Inactive") is neither
+// active nor terminal.
+func SessionStatusIsTerminal(status string) bool {
+	switch normalizeSessionStatus(status) {
+	case "finished", "finalised", "finalized", "ends", "aborted":
+		return true
+	default:
+		return false
+	}
+}
+
 func normalizeSessionStatus(status string) string {
 	out := make([]rune, 0, len(status))
 	for _, r := range status {

internal/query/racehub.go

@@ -252,10 +252,38 @@ func (s *Service) GetRaceHub(sessionKey int) (RaceHub, error) {
 	}
 
 	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 {

internal/web/live.go

@@ -134,7 +134,7 @@ func (h *SSEHub) applySnapshot(data live.LiveStreamData, now time.Time) liveStat
 	h.mu.Lock()
 	defer h.mu.Unlock()
 
-	if live.SessionStatusIsActive(data.SessionStatus) {
+	if snapshotIsLive(data) {
 		h.isLive = true
 		h.activeSnapshot = &data
 		if data.PositionUpdated && len(data.Positions) > 0 {
@@ -208,6 +208,40 @@ func (h *SSEHub) stateLocked() liveStatePayload {
 	return payload
 }
 
+// snapshotIsLive reports whether the current live-timing snapshot represents an
+// ongoing session that should be surfaced as live.
+//
+// An actively running session (Started/Resumed) is always live. A non-terminal
+// but temporarily inactive session — e.g. a red-flag pause where SessionStatus
+// drops to "Inactive" while the session is still in progress — is also live when
+// the snapshot itself carries live evidence: a session clock with time remaining
+// plus session metadata. This keeps the paused track state visible instead of
+// collapsing to the inactive empty state.
+//
+// Terminal sessions (Finished/Finalised/Ends/Aborted) are never live. A generic
+// inactive/no-session stale snapshot is not live either: the predicate keys off
+// the current snapshot's clock and session, so old metadata alone is not enough.
+func snapshotIsLive(data live.LiveStreamData) bool {
+	if live.SessionStatusIsActive(data.SessionStatus) {
+		return true
+	}
+	if live.SessionStatusIsTerminal(data.SessionStatus) {
+		return false
+	}
+	return clockHasTimeRemaining(data.Clock) && data.Session.SessionName != ""
+}
+
+// clockHasTimeRemaining reports whether an "HH:MM:SS" session clock has any time
+// left. Empty or all-zero clocks (a spent or absent session) return false.
+func clockHasTimeRemaining(clock string) bool {
+	for _, r := range clock {
+		if r >= '1' && r <= '9' {
+			return true
+		}
+	}
+	return false
+}
+
 func hasLiveSnapshotData(data live.LiveStreamData) bool {
 	return len(data.Drivers) > 0 ||
 		len(data.DriverInfo) > 0 ||

internal/web/live_archive_test.go

@@ -51,6 +51,101 @@ func TestSSEHubArchivesTerminalSessionSnapshot(t *testing.T) {
 	}
 }
 
+func TestSnapshotIsLive(t *testing.T) {
+	redFlag := live.LiveStreamData{
+		SessionStatus: "Inactive",
+		TrackStatus:   "2",
+		Clock:         "00:03:27",
+		Session:       live.LiveSessionMeta{MeetingName: "Belgian Grand Prix", SessionName: "Practice 2", SessionType: "Practice"},
+	}
+	tests := []struct {
+		name string
+		data live.LiveStreamData
+		want bool
+	}{
+		{"started", live.LiveStreamData{SessionStatus: "Started"}, true},
+		{"resumed", live.LiveStreamData{SessionStatus: "Resumed"}, true},
+		{"red flag inactive with clock and session", redFlag, true},
+		{"terminal finished with clock", func() live.LiveStreamData {
+			d := redFlag
+			d.SessionStatus = "Finished"
+			return d
+		}(), false},
+		{"inactive spent clock", func() live.LiveStreamData {
+			d := redFlag
+			d.Clock = "00:00:00"
+			return d
+		}(), false},
+		{"inactive no clock", func() live.LiveStreamData {
+			d := redFlag
+			d.Clock = ""
+			return d
+		}(), false},
+		{"inactive no session metadata", func() live.LiveStreamData {
+			d := redFlag
+			d.Session = live.LiveSessionMeta{}
+			return d
+		}(), false},
+	}
+	for _, tt := range tests {
+		if got := snapshotIsLive(tt.data); got != tt.want {
+			t.Errorf("%s: snapshotIsLive = %v, want %v", tt.name, got, tt.want)
+		}
+	}
+}
+
+func TestSSEHubKeepsRedFlagSessionLive(t *testing.T) {
+	hub := newSSEHub()
+	now := time.Date(2026, 7, 26, 14, 0, 0, 0, time.UTC)
+
+	redFlag := live.LiveStreamData{
+		SessionStatus:   "Inactive",
+		TrackStatus:     "2",
+		Clock:           "00:03:27",
+		Session:         live.LiveSessionMeta{MeetingName: "Belgian Grand Prix", SessionName: "Practice 2", SessionType: "Practice"},
+		SnapshotUpdated: true,
+	}
+	state := hub.applySnapshot(redFlag, now)
+
+	if !state.IsLive {
+		t.Fatal("red-flag paused session should report is_live=true")
+	}
+	if state.Data == nil {
+		t.Fatal("red-flag paused session must still send the active snapshot")
+	}
+	if state.Data.TrackStatus != "2" {
+		t.Fatalf("track status = %q, want the paused state \"2\"", state.Data.TrackStatus)
+	}
+	if state.LastSnapshot != nil {
+		t.Fatalf("red-flag session should not be archived: %+v", state.LastSnapshot)
+	}
+}
+
+func TestSSEHubStaleInactiveSnapshotNotLive(t *testing.T) {
+	hub := newSSEHub()
+	now := time.Date(2026, 7, 26, 14, 0, 0, 0, time.UTC)
+
+	// Inactive snapshot with session metadata but no remaining clock: this is a
+	// stale/no-live-evidence snapshot and must not be surfaced as live.
+	stale := live.LiveStreamData{
+		SessionStatus:   "Inactive",
+		Clock:           "00:00:00",
+		Session:         live.LiveSessionMeta{MeetingName: "Belgian Grand Prix", SessionName: "Practice 2"},
+		SnapshotUpdated: true,
+	}
+	state := hub.applySnapshot(stale, now)
+
+	if state.IsLive {
+		t.Fatal("stale inactive snapshot should report is_live=false")
+	}
+	if state.Data != nil {
+		t.Fatalf("stale inactive snapshot leaked into active data: %+v", state.Data)
+	}
+	if state.LastSnapshot == nil {
+		t.Fatal("stale inactive snapshot with metadata should be archived")
+	}
+}
+
 func TestHandleLiveStateKeepsArchiveOutOfActiveData(t *testing.T) {
 	hub := newSSEHub()
 	now := time.Date(2026, 7, 4, 14, 0, 0, 0, time.UTC)

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

@@ -78,6 +78,7 @@ func (s *Server) routes() (http.Handler, error) {
 	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)

tests/live-timing.spec.ts

@@ -147,6 +147,58 @@ const sprintQualifyingSnapshot = {
   },
 }
 
+// Practice: the feed sets best laps but no GapToLeader/Interval, and there is
+// no race lap-total concept. Exercises computed gaps, the non-race banner, the
+// collapsed-by-default tyre panel, and the 390px core-field layout.
+const practiceSnapshot = {
+  is_live: true,
+  data: {
+    ...raceSnapshot.data,
+    Drivers: Object.fromEntries(
+      Array.from({ length: 10 }, (_, index) => {
+        const num = String(index + 1)
+        return [
+          num,
+          driver(num, index + 1, '', '', {
+            // Distinct, increasing best laps; P1 fastest, +0.200s per position.
+            BestLapTime: `1:${(45.9 + index * 0.2).toFixed(3).padStart(6, '0')}`,
+            LastLapTime: '1:46.500',
+            NumberOfLaps: 12,
+            Sectors: index === 0
+              ? [
+                  { Value: '28.500', PersonalFastest: true, OverallFastest: false },
+                  { Value: '52.100', PersonalFastest: false, OverallFastest: false },
+                  { Value: '25.344', PersonalFastest: false, OverallFastest: false },
+                ]
+              : [],
+          }),
+        ]
+      }),
+    ),
+    DriverInfo: Object.fromEntries(
+      Array.from({ length: 10 }, (_, index) => {
+        const num = String(index + 1)
+        return [num, info(num, `D${index + 1}`, 'Driver', String(index + 1), 'Test Team', index % 2 ? 'FF8000' : '27F4D2')]
+      }),
+    ),
+    Tyres: Object.fromEntries(
+      Array.from({ length: 10 }, (_, index) => [String(index + 1), { Compound: 'SOFT', New: false, Age: index % 4 }]),
+    ),
+    Session: {
+      MeetingName: 'Belgian Grand Prix',
+      CircuitName: 'Spa-Francorchamps',
+      SessionType: 'Practice',
+      SessionName: 'Practice 2',
+    },
+    TrackStatus: '1',
+    CurrentLap: 0,
+    TotalLaps: 0,
+    Clock: '00:45:00',
+    ClockRefTime: '2026-07-17T13:00:00Z',
+    ClockExtrapolating: false,
+  },
+}
+
 test.describe('Live Timing (mocked snapshot)', () => {
   test.beforeEach(async ({ page }) => {
     await page.route('**/api/v1/live/state', (route) =>
@@ -233,6 +285,94 @@ test.describe('Live Timing (mocked Sprint Qualifying)', () => {
   })
 })
 
+test.describe('Live Timing (mocked Practice)', () => {
+  test.beforeEach(async ({ page }) => {
+    await page.route('**/api/v1/live/state', (route) =>
+      route.fulfill({ contentType: 'application/json', body: JSON.stringify(practiceSnapshot) }),
+    )
+    await page.route('**/api/v1/live/stream', (route) =>
+      route.fulfill({ contentType: 'text/event-stream', body: 'event: heartbeat\ndata: {}\n\n' }),
+    )
+    await page.goto('/live')
+  })
+
+  test('derives a gap to P1 from best laps and marks the leader', async ({ page }) => {
+    const tower = page.locator('.live-tower')
+    await expect(tower).toBeVisible()
+    // P1 shows a leader marker, not a fabricated gap.
+    await expect(tower.locator('tbody tr').first()).toContainText('—')
+    // P2 shows the computed +0.200 delta.
+    await expect(tower).toContainText('+0.200')
+  })
+
+  test('omits the race lap counter and keeps the session clock for practice', async ({ page }) => {
+    await expect(page.getByTestId('live-lap-counter')).toHaveCount(0)
+    await expect(page.getByTestId('live-clock')).toContainText('00:45:00')
+    await expect(page.locator('.live-banner')).not.toContainText('L-/-')
+  })
+
+  test('collapses the tyre panel by default so the tower is above the fold', async ({ page }) => {
+    await expect(page.getByTestId('tyredeg-panel')).toBeVisible()
+    await expect(page.getByTestId('tyredeg-row')).toHaveCount(0)
+    await expect(page.locator('.live-tower')).toBeVisible()
+  })
+
+  test('labels Race Control times as UTC', async ({ page }) => {
+    await expect(page.getByTestId('rc-timezone')).toContainText('UTC')
+  })
+
+  test('marks Live as active in the primary navigation', async ({ page }) => {
+    await expect(page.getByTestId('nav-live')).toHaveAttribute('data-live-active', 'true')
+    await expect(page.getByTestId('nav-live').locator('.nav-live-dot')).toBeVisible()
+  })
+})
+
+test.describe('Live Timing (390px practice viewport)', () => {
+  test.use({ viewport: { width: 390, height: 844 } })
+
+  test.beforeEach(async ({ page }) => {
+    await page.route('**/api/v1/live/state', (route) =>
+      route.fulfill({ contentType: 'application/json', body: JSON.stringify(practiceSnapshot) }),
+    )
+    await page.route('**/api/v1/live/stream', (route) =>
+      route.fulfill({ contentType: 'text/event-stream', body: 'event: heartbeat\ndata: {}\n\n' }),
+    )
+    await page.goto('/live')
+  })
+
+  test('shows the five core fields with no horizontal overflow', async ({ page }) => {
+    const tower = page.locator('.live-tower')
+    await expect(tower).toBeVisible()
+
+    // Core comparison fields are present in the header.
+    await expect(tower.locator('thead')).toContainText('Pos')
+    await expect(tower.locator('thead')).toContainText('Driver')
+    await expect(tower.locator('thead')).toContainText('Tyre')
+    await expect(tower.locator('thead')).toContainText('Best')
+    await expect(tower.locator('thead')).toContainText('Gap to P1')
+
+    // Sectors are hidden from the initial mobile tower (reachable via expand).
+    const firstSector = tower.locator('thead th', { hasText: 'S1' })
+    await expect(firstSector).toBeHidden()
+
+    // The document must not scroll horizontally.
+    const overflow = await page.evaluate(
+      () => document.documentElement.scrollWidth - document.documentElement.clientWidth,
+    )
+    expect(overflow).toBeLessThanOrEqual(0)
+  })
+
+  test('exposes sectors through the row detail interaction', async ({ page }) => {
+    // Sector columns are not in the initial mobile tower...
+    await expect(page.locator('.live-tower thead th', { hasText: 'S1' })).toBeHidden()
+    // ...but the P1 row's sectors are reachable by expanding the row.
+    await page.locator('.live-tower tbody tr', { hasText: 'D1' }).first().click()
+    const sectors = page.getByTestId('expanded-sectors')
+    await expect(sectors).toBeVisible()
+    await expect(sectors).toContainText('28.500')
+  })
+})
+
 test.describe('Live Timing (no session)', () => {
   test('shows the empty state when the feed has no snapshot', async ({ page }) => {
     await page.goto('/live')

tests/race-hub.spec.ts

@@ -39,7 +39,17 @@ test.describe('Race Hub Weekend Workspace', () => {
     await expect(
       page.getByRole('img', { name: 'Position evolution chart' }),
     ).toBeVisible()
-    await expect(page.getByText('Lap-by-lap positions not available.')).not.toBeVisible()
+    await expect(page.getByTestId('race-story-no-positions')).not.toBeVisible()
+  })
+
+  test('Race Story highlights a chapter card when clicked', async ({ page }) => {
+    await page.goto(`/race-hub?session_key=${FULL_SESSION}`)
+    await page.getByRole('tab', { name: 'Race Story' }).click()
+
+    const firstCard = page.getByTestId('chapter-card-0')
+    await expect(firstCard).toBeVisible()
+    await firstCard.click()
+    await expect(firstCard).toHaveClass(/active/)
   })
 
   test('strategy tab renders stint chart when stints are available', async ({ page }) => {
@@ -58,13 +68,15 @@ test.describe('Race Hub Weekend Workspace', () => {
     await expect(page.locator('[data-testid="strategy-chart"]')).not.toBeVisible()
   })
 
-  test('Race Story shows missing notice when positions are unavailable', async ({
+  test('Race Story shows empty-state card when positions are unavailable', async ({
     page,
   }) => {
     await page.goto(`/race-hub?session_key=${CORE_ONLY_SESSION}`)
     await page.getByRole('tab', { name: 'Race Story' }).click()
 
-    await expect(page.getByText('Lap-by-lap positions not available.')).toBeVisible()
+    const empty = page.getByTestId('race-story-no-positions')
+    await expect(empty).toBeVisible()
+    await expect(empty.getByText('Lap-by-lap positions not available')).toBeVisible()
     await expect(page.locator('[data-testid="position-chart"]')).not.toBeVisible()
   })
 

tests/visual/helpers.ts

@@ -36,6 +36,14 @@ export async function gotoRaceHubReady(page: Page, sessionKey = FULL_SESSION): P
   await waitForScreenshotReady(page)
 }
 
+export async function gotoRaceStoryReady(page: Page, sessionKey = FULL_SESSION): Promise<void> {
+  await page.goto(`/race-hub?session_key=${sessionKey}`)
+  await expect(page.getByTestId('race-hub')).toBeVisible()
+  await page.getByRole('tab', { name: 'Race Story' }).click()
+  await expect(page.getByTestId('position-chart')).toBeVisible()
+  await waitForScreenshotReady(page)
+}
+
 export async function gotoDataLibraryReady(page: Page): Promise<void> {
   await page.goto('/admin')
   await expect(page.getByTestId('data-library')).toBeVisible()

tests/visual/race-story.spec.ts

@@ -0,0 +1,9 @@
+import { test } from '@playwright/test'
+import { gotoRaceStoryReady, screenshotPage } from './helpers'
+
+test.describe('Race Story visual regression', () => {
+  test('race-story', async ({ page }) => {
+    await gotoRaceStoryReady(page)
+    await screenshotPage(page, 'race-story')
+  })
+})