Session 52: Coming Soon teaser + infrastructure verification (2239 tests)

Phase 1 — Push-to-Book teaser (feature not live; teaser only):
- StatStrip: "BOOK IT ⟶" per graded prop (hover: "Push-to-Book coming soon").
- GradeResultCard: "PUSH-TO-BOOK · COMING SOON" footer.

Phase 2 — infrastructure verification:
- snapshotScheduler logs armed AND disarmed state (incl SNAPSHOT_CRON) so
  container logs disambiguate off-vs-crashed.
- NEW GET /api/internal/snapshot/status (internal-key gated): cron_armed,
  cron_hours_utc, last_snapshot per sport (gradeCount/deltaCount), redis_keys
  existence map, ticker_count. The post-deploy pipeline health probe.
- Finding: Redis AOF/RDB persistence is a server-side (Coolify) config the app
  can't set/verify — documented.

Phase 3 — delta pipeline (verified sound, no fix needed):
- runSnapshot already rotates :latest->:previous and diffs locked lines; added
  opt-in SNAPSHOT_DEBUG=1 [deltas] log + a trace test asserting :previous is
  preserved verbatim and the delta math is correct.

Backend 2234 -> 2239 tests (+5), 192 suites. Web build clean (exit 0).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/unit/snapshotScheduler.test.js

@@ -14,6 +14,16 @@ describe('startSnapshotScheduler', () => {
     expect(HOURS_UTC).toEqual([14, 19, 22, 1, 3]);
   });
 
+  it('logs an armed startup message including SNAPSHOT_CRON when started', () => {
+    process.env.SNAPSHOT_CRON = '1';
+    const spy = jest.spyOn(console, 'log').mockImplementation(() => {});
+    const sched = startSnapshotScheduler({ runAllSnapshots: jest.fn(), now: () => new Date(Date.UTC(2026, 5, 18, 12, 30, 0)) });
+    expect(spy).toHaveBeenCalledWith(expect.stringContaining('[snapshotScheduler] armed'));
+    expect(spy).toHaveBeenCalledWith(expect.stringContaining('SNAPSHOT_CRON=1'));
+    spy.mockRestore();
+    if (sched && sched.interval && sched.interval.unref) clearInterval(sched.interval);
+  });
+
   it('fires runAllSnapshots at a scheduled hour, once per slot', async () => {
     process.env.SNAPSHOT_CRON = '1';
     const runAllSnapshots = jest.fn(async () => [{ sport: 'mlb', status: 'ok' }]);