fix(#98): rearm capped race hub refresh

frontend/src/lib/schedule.ts

@@ -145,11 +145,13 @@ export function formatSessionScheduleTime(value: string): string {
   })
 }
 
+export const MAX_BROWSER_TIMEOUT = 2_147_483_647
+
 export function refreshDeadlineDelay(refreshAt: string | undefined, now = Date.now()): number | null {
   if (!refreshAt) return null
   const deadline = Date.parse(refreshAt)
   if (Number.isNaN(deadline)) return null
-  return Math.min(Math.max(0, deadline - now), 2_147_483_647)
+  return Math.min(Math.max(0, deadline - now), MAX_BROWSER_TIMEOUT)
 }
 
 export type FocusMeetingKind = 'current' | 'next' | 'recent' | 'fallback'

frontend/src/pages/RaceHubPage.tsx

@@ -17,6 +17,7 @@ import { SourceBadge } from '../components/SourceBadge'
 import { countryAccent, countryDecal, formatGpDateRange } from '../lib/gpIdentity'
 import { formatCoverageHint, sessionTypeAbbrev } from '../lib/coverage'
 import {
+  MAX_BROWSER_TIMEOUT,
   formatCountdown,
   formatSessionScheduleTime,
   refreshDeadlineDelay,
@@ -33,6 +34,7 @@ export function RaceHubPage({ sessionKey }: Props) {
   const [activeTab, setActiveTab] = useState<Tab>('overview')
   const [switcherOpen, setSwitcherOpen] = useState(false)
   const [now, setNow] = useState(() => Date.now())
+  const [refreshGeneration, setRefreshGeneration] = useState(0)
 
   // The server owns bare Race Hub selection so every open tab crosses the
   // one-hour handoff at the same instant.
@@ -57,9 +59,14 @@ export function RaceHubPage({ sessionKey }: Props) {
     if (sessionKey !== 0) return
     const delay = refreshDeadlineDelay(context?.race_hub_refresh_at)
     if (delay == null) return
-    const timer = window.setTimeout(() => { void refetchContext() }, delay)
+    const rearmAfterRefetch = delay === MAX_BROWSER_TIMEOUT
+    const timer = window.setTimeout(() => {
+      void refetchContext().finally(() => {
+        if (rearmAfterRefetch) setRefreshGeneration((generation) => generation + 1)
+      })
+    }, delay)
     return () => window.clearTimeout(timer)
-  }, [sessionKey, context?.race_hub_refresh_at, refetchContext])
+  }, [sessionKey, context?.race_hub_refresh_at, refetchContext, refreshGeneration])
 
   useEffect(() => {
     if (!preSession) return

frontend/src/test/RaceHubPage.test.tsx

@@ -9,6 +9,7 @@ import {
   createRoute,
 } from '@tanstack/react-router'
 import { RaceHubPage } from '../pages/RaceHubPage'
+import { MAX_BROWSER_TIMEOUT } from '../lib/schedule'
 import type { ContextAvailability, DatasetInfo, Meeting, RaceHub, Session, Weekend, WeekendContext } from '../types'
 
 vi.mock('../api', () => ({
@@ -375,6 +376,22 @@ describe('RaceHubPage', () => {
     expect(mockFetchRaceHub).not.toHaveBeenCalledWith(9473)
   })
 
+  it('re-arms a bare route refresh after a capped browser timer', async () => {
+    vi.useFakeTimers({ shouldAdvanceTime: true })
+    mockFetchWeekendContext.mockResolvedValue({
+      ...analysisContext,
+      race_hub_refresh_at: new Date(Date.now() + MAX_BROWSER_TIMEOUT + 1_000).toISOString(),
+    })
+
+    renderRaceHub(0)
+    await screen.findByTestId('race-hub')
+    await act(async () => { await vi.advanceTimersByTimeAsync(MAX_BROWSER_TIMEOUT) })
+
+    await waitFor(() => expect(mockFetchWeekendContext).toHaveBeenCalledTimes(2))
+    await act(async () => { await vi.advanceTimersByTimeAsync(1_000) })
+    await waitFor(() => expect(mockFetchWeekendContext).toHaveBeenCalledTimes(3))
+  })
+
   it('keeps an explicit session URL stable across the canonical refresh boundary', async () => {
     vi.useFakeTimers()
     renderRaceHub(9472)

frontend/src/test/schedule.test.ts

@@ -5,6 +5,7 @@ import {
   focusMeetingKind,
   focusMeetingLabel,
   formatCountdown,
+  MAX_BROWSER_TIMEOUT,
   nextUpcomingMeeting,
   pickFocusMeeting,
   refreshDeadlineDelay,
@@ -84,4 +85,10 @@ describe('schedule helpers', () => {
     expect(refreshDeadlineDelay('2025-05-25T13:00:00Z', Date.parse('2025-05-25T12:59:30Z'))).toBe(30_000)
     expect(refreshDeadlineDelay(undefined)).toBeNull()
   })
+
+  it('caps a refresh deadline beyond the browser timer maximum', () => {
+    const now = Date.parse('2025-05-25T12:00:00Z')
+    const deadline = new Date(now + MAX_BROWSER_TIMEOUT + 1_000).toISOString()
+    expect(refreshDeadlineDelay(deadline, now)).toBe(MAX_BROWSER_TIMEOUT)
+  })
 })