fix(race-hub): consume canonical weekend context for #75 review

Address PR #82 review blockers: drop the competing /weekend
default_analysis_session resolver, land bare /race-hub via
/api/v1/weekend-context, derive Live/preparing/partial/unavailable from
authoritative context with a moving clock, hide Local Coverage behind
Diagnostics, isolate the future-session fixture from the shared seed,
and strengthen return-to-Weekend context coverage.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/fixtures/future-session.ts

@@ -0,0 +1,78 @@
+import type { Page } from '@playwright/test'
+
+/** Isolated future-session key — not present in the shared e2e seed DB. */
+export const FUTURE_SESSION = 9600
+export const FUTURE_MEETING = 1300
+
+const emptyDatasets = {}
+
+const futureMeeting = {
+  meeting_key: FUTURE_MEETING,
+  meeting_name: 'Future Grand Prix',
+  meeting_official_name: 'FORMULA 1 FUTURE GRAND PRIX 2099',
+  location: 'Futureville',
+  country_name: 'Testland',
+  country_code: 'TST',
+  country_flag: '',
+  circuit_short_name: 'Future',
+  date_start: '2099-05-23T00:00:00+00:00',
+  date_end: '2099-05-25T00:00:00+00:00',
+  year: 2099,
+}
+
+const futureSession = {
+  session_key: FUTURE_SESSION,
+  session_name: 'Race',
+  session_type: 'Race',
+  meeting_key: FUTURE_MEETING,
+  date_start: '2099-05-25T13:00:00+00:00',
+  date_end: '2099-05-25T15:00:00+00:00',
+  gmt_offset: '00:00:00',
+}
+
+const futureRaceHub = {
+  source: 'none',
+  session_key: FUTURE_SESSION,
+  datasets: emptyDatasets,
+  meeting: futureMeeting,
+  session: futureSession,
+  drivers: [],
+  results: [],
+  starting_grid: [],
+  stints: [],
+  pit_stops: [],
+  positions: [],
+  race_control: [],
+  weather: [],
+  laps: [],
+  chapters: [],
+}
+
+const futureWeekend = {
+  source: 'none',
+  meeting_key: FUTURE_MEETING,
+  meeting: futureMeeting,
+  default_session_key: FUTURE_SESSION,
+  sessions: [{ session: futureSession, source: 'none', datasets: emptyDatasets }],
+}
+
+/**
+ * Route-mock a far-future session without contaminating the shared Monaco seed
+ * (which would rewrite Command Center / Data Library baselines).
+ */
+export async function mockFutureRaceHubSession(page: Page): Promise<void> {
+  await page.route(`**/api/v1/race-hub?session_key=${FUTURE_SESSION}`, async (route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify(futureRaceHub),
+    })
+  })
+  await page.route(`**/api/v1/weekend?meeting_key=${FUTURE_MEETING}`, async (route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify(futureWeekend),
+    })
+  })
+}