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>

CLAUDE.md

@@ -577,6 +577,22 @@ snapshot, locked to the line, and read from cache.
   `vyndr/GameCard`'s `TeamLink` (stops propagation from the open-game handler).
   The roster "+" reuses the Parlay Lab (`useParlay`/`legKey`).
 
+## Infra Verification (Session 52 — non-obvious)
+- **`GET /api/internal/snapshot/status`** (internal-key gated) is the post-deploy
+  health probe: `{ cron_armed, cron_hours_utc, last_snapshot, redis_keys,
+  ticker_count }`. Use it to confirm the snapshot pipeline is alive without
+  shelling into the container.
+- **Scheduler logs both states** on start: armed (`[snapshotScheduler] armed —
+  SNAPSHOT_CRON=…`) and disarmed. If you see neither in container logs,
+  `startSnapshotScheduler()` isn't being called.
+- **`SNAPSHOT_DEBUG=1`** turns on a per-run `[deltas]` log in `computeLineDeltas`
+  (off by default — it's a hot path). Confirms a previous snapshot exists to diff.
+- **Redis persistence is NOT app-controlled.** ioredis connects via `REDIS_URL`;
+  AOF/RDB is a server-side Coolify config. Snapshot keys disappearing on restart
+  = the Redis instance has persistence off, not a code bug.
+- **Push-to-Book is a TEASER only** — "BOOK IT ⟶" (StatStrip) + "PUSH-TO-BOOK ·
+  COMING SOON" (GradeResultCard) advertise an unbuilt feature. No backend.
+
 ## Active Skills
 - vyndr-voice (all user-facing output)
 - prop-analysis (grading methodology)