feat(race-hub): trustworthy defaults and fan-facing analysis hierarchy (#75)

Make bare /race-hub resolve to a completed session and never open empty
post-session analysis for a future race.

- Backend: add `default_analysis_session` to the Weekend context. It never
  resolves to a future session (picks the richest completed session, ties
  toward the later one; 0 when everything is upcoming). Existing
  `default_session_key` and deep links are unchanged.
- Frontend default resolution prefers the most recently completed weekend
  (`pickAnalysisFocusMeeting`) and consumes `default_analysis_session`, falling
  back to the switcher when only upcoming sessions exist.
- New `sessionState` lib maps timing + coverage to user language
  (upcoming/live/preparing/partial/ready/cancelled); the session rail, active
  sub-bar, and WeekendSwitcher now label states instead of raw x/11 counts.
- Future sessions render a purpose-built PreSessionView (expected availability +
  countdown) instead of empty Winner/Podium/Pole/Strategy/Compare cards.
- Analysis navigation regrouped into Story / Analysis / Data & Context; every
  existing tab is preserved. Diagnostics (renamed from Data Status) is now a
  secondary action and the raw dataset strip is hidden behind an explicit
  toggle, so operational coverage no longer precedes fan content.
- Loading/error states offer Retry and a path back to Weekend.

Tests: Go query tests for future-exclusion; Vitest for default selection,
future pre-session, partial state, error/retry, grouped nav, and sessionState;
hermetic Playwright for bare/completed/future/return-to-Weekend; new
race-hub-future visual snapshots. Seed adds a far-future session inside the
Monaco meeting (kept in-meeting so Command Center focus is unaffected).

Note: `default_analysis_session` is an additive field on the existing
`/weekend` contract (no new endpoint), per the spec's "context contract" scope.

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

scripts/seed-e2e-db/main.go

@@ -30,6 +30,11 @@ func main() {
 	const meetingKey = 1229
 	const fullSessionKey = 9472
 	const coreOnlySessionKey = 9000
+	// A far-future session inside the same Monaco meeting so bare /race-hub never
+	// lands on it (default_analysis_session picks the completed race) yet an
+	// explicit deep link renders the dedicated pre-session view. Kept in the same
+	// meeting so the Command Center's focus selection is unaffected.
+	const futureSessionKey = 9600
 
 	if err := seedMeeting(st, meetingKey); err != nil {
 		fail(err)
@@ -59,6 +64,10 @@ func main() {
 		fail(err)
 	}
 
+	if err := seedFutureSession(st, futureSessionKey, meetingKey); err != nil {
+		fail(err)
+	}
+
 	fmt.Printf("seeded e2e db at %s\n", *dbPath)
 }
 
@@ -95,6 +104,20 @@ func seedSession(st *store.Store, sessionKey, meetingKey int, name string) error
 	})
 }
 
+func seedFutureSession(st *store.Store, sessionKey, meetingKey int) error {
+	// Far-future date so this session is always "upcoming" relative to the wall
+	// clock and renders the pre-session view on an explicit deep link.
+	return st.UpsertSession(store.Session{
+		SessionKey:  sessionKey,
+		MeetingKey:  meetingKey,
+		SessionName: "Future Sprint",
+		SessionType: "Race",
+		CircuitKey:  10,
+		DateStart:   "2099-05-25T13:00:00+00:00",
+		DateEnd:     "2099-05-25T15:00:00+00:00",
+	})
+}
+
 func seedDrivers(st *store.Store, sessionKey, meetingKey int) error {
 	drivers := []store.Driver{
 		{