fix: separate live archive snapshots

Parse and expose SessionStatus from the official live feed, treating Started/Resumed as active and terminal or missing statuses as inactive archive candidates.

Keep /api/v1/live/state and SSE snapshot data reserved for active sessions while exposing memory-only last_snapshot, last_positions, and last_snapshot_at for the explicit Live tab archive view.

frontend/src/test/LiveTimingPage.test.tsx

@@ -0,0 +1,155 @@
+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 { LiveTimingPage } from '../pages/LiveTimingPage'
+import type { LiveStateResponse, LiveStreamData } from '../types'
+
+vi.mock('../api', () => ({
+  fetchLiveState: vi.fn(),
+  fetchLiveTrackOutline: vi.fn(),
+}))
+
+import { fetchLiveState, fetchLiveTrackOutline } from '../api'
+
+const mockFetchLiveState = vi.mocked(fetchLiveState)
+const mockFetchLiveTrackOutline = vi.mocked(fetchLiveTrackOutline)
+
+class MockEventSource {
+  onopen: (() => void) | null = null
+  onerror: (() => void) | null = null
+
+  constructor() {
+    setTimeout(() => this.onopen?.(), 0)
+  }
+
+  addEventListener() {}
+  close() {}
+}
+
+const archivedSnapshot: LiveStreamData = {
+  Drivers: {
+    '1': {
+      RacingNumber: '1',
+      Position: 1,
+      PrevPosition: 1,
+      GapToLeader: '',
+      Interval: '',
+      LastLapTime: '1:21.345',
+      LastLapPB: false,
+      LastLapOB: false,
+      BestLapTime: '1:20.987',
+      BestLapPB: false,
+      BestLapOB: false,
+      BestLapNum: 22,
+      InPit: false,
+      PitOut: false,
+      Retired: false,
+      KnockedOut: false,
+      Cutoff: false,
+      OnFlyingLap: false,
+      NumberOfLaps: 30,
+      SpeedTrap: '',
+      Sectors: [],
+    },
+  },
+  DriverInfo: {
+    '1': {
+      RacingNumber: '1',
+      BroadcastName: 'M VERSTAPPEN',
+      Tla: 'VER',
+      TeamName: 'Red Bull Racing',
+      TeamColour: '3671C6',
+      FirstName: 'Max',
+      LastName: 'Verstappen',
+    },
+  },
+  Tyres: {
+    '1': { Compound: 'HARD', New: false, Age: 12 },
+  },
+  Telemetry: {},
+  RCMessages: [],
+  Weather: {
+    AirTemp: 22,
+    TrackTemp: 41,
+    Humidity: 58,
+    WindSpeed: 3,
+    WindDir: 180,
+    Rainfall: false,
+  },
+  Session: {
+    MeetingName: 'Testonia Grand Prix',
+    CircuitName: 'Testring',
+    SessionType: 'Race',
+    SessionName: 'Race',
+    Path: '',
+  },
+  TeamRadio: [],
+  SessionStatus: 'Finished',
+  TrackStatus: '1',
+  CurrentLap: 57,
+  TotalLaps: 57,
+  Clock: '',
+  ClockRefTime: '',
+  ClockExtrapolating: false,
+  Stints: {},
+}
+
+function renderPage(response: LiveStateResponse) {
+  const queryClient = new QueryClient({
+    defaultOptions: { queries: { retry: false } },
+  })
+  mockFetchLiveState.mockResolvedValue(response)
+  mockFetchLiveTrackOutline.mockResolvedValue({
+    circuit_key: 1,
+    points: [],
+    bounds: { minX: 0, maxX: 1, minY: 0, maxY: 1 },
+  })
+
+  return render(
+    <QueryClientProvider client={queryClient}>
+      <LiveTimingPage />
+    </QueryClientProvider>,
+  )
+}
+
+describe('LiveTimingPage archive mode', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    Object.defineProperty(window, 'EventSource', {
+      value: MockEventSource,
+      writable: true,
+      configurable: true,
+    })
+  })
+
+  it('keeps archived snapshots behind the View Last Session action', async () => {
+    renderPage({
+      is_live: false,
+      data: null,
+      last_snapshot: archivedSnapshot,
+      last_positions: {
+        '1': { x: 10, y: 20, z: 0, status: 'OnTrack' },
+      },
+      last_snapshot_at: '2026-07-04T14:00:00Z',
+    })
+
+    expect(await screen.findByTestId('live-empty')).toHaveTextContent('No live session active')
+    expect(screen.queryByText('Timing Tower')).not.toBeInTheDocument()
+
+    fireEvent.click(screen.getByRole('button', { name: /view last session/i }))
+
+    await waitFor(() => {
+      expect(screen.getByTestId('live-archive-strip')).toHaveTextContent('Archived snapshot')
+    })
+    expect(screen.getByText('Timing Tower')).toBeInTheDocument()
+    expect(screen.getAllByText('VER').length).toBeGreaterThan(0)
+    expect(screen.getByText('archive')).toBeInTheDocument()
+  })
+
+  it('does not show the archive action when no snapshot is retained', async () => {
+    renderPage({ is_live: false, data: null })
+
+    expect(await screen.findByTestId('live-empty')).toHaveTextContent('No live session active')
+    expect(screen.queryByRole('button', { name: /view last session/i })).not.toBeInTheDocument()
+  })
+})

frontend/src/test/live.test.ts

@@ -163,6 +163,20 @@ describe('live transforms', () => {
     expect(parsed?.data?.Drivers['16'].RacingNumber).toBe('16')
   })
 
+  it('parses archived EventSource snapshots separately from active data', () => {
+    const parsed = parseLiveStateEvent(JSON.stringify({
+      is_live: false,
+      data: null,
+      last_snapshot: snapshot,
+      last_positions: { '16': { x: 1, y: 2, z: 3, status: 'OnTrack' } },
+      last_snapshot_at: '2026-07-04T14:00:00Z',
+    }))
+    expect(parsed?.is_live).toBe(false)
+    expect(parsed?.data).toBeNull()
+    expect(parsed?.last_snapshot?.Drivers['16'].RacingNumber).toBe('16')
+    expect(parsed?.last_positions?.['16'].status).toBe('OnTrack')
+  })
+
   it('sorts timing rows by live position and includes drivers with metadata only', () => {
     const rows = sortLiveTimingRows(snapshot)
     expect(rows.map((row) => row.RacingNumber)).toEqual(['16', '1', '44'])