Suppress rare-event 0.5 unders (juiced, no-edge) — config-driven grade + board fix

Betting-logic audit: the CONSENSUS-vs-MODEL board flooded with fake reads like
"DOUBLES u0.5 · MODEL 0.2 · +edge" — the juiced under side of rare counting-stat
markets (doubles/triples/HR/SB), which is never a takeable edge and violates the
no-unders-default doctrine.

Report finding (item 3/4): the doubles projection is REAL per-player, not a flat
fallback — 'doubles' maps to a real game-log field (MLB_LOG_FIELD doubles→
doubles) and the live values varied (0.03/0.16/0.2/0.22). So no projection-gate
refusal for fakeness; the problem is purely structural (a rare event's real
projection always sits below a 0.5 line, so the under always "wins").

Fix (config-driven — src/config/rareEventMarkets.js, tunable stat list + line
threshold):
- Grade layer (analyzeViaEngine1): a rare-event UNDER at ≤0.5 is always REFUSED
  (grade null + suppressed flag/reason). A rare-event OVER at ≤0.5 is refused
  UNLESS the model genuinely projects the event above the line — because a
  0.2-over-0.5 carries the SAME |edge| as the suppressed under and would just
  take its rank on the board. The over grades normally once projection > line.
- Board layer (marketBreadth.collectBreadth): drops null-model rows so a
  suppressed/ungraded prop can't rank a "MODEL —" placeholder onto the board.

10 suppression tests + config locks; also fixed a settingsPage book assertion
left over from the ESPN→theScore swap. Suite 274/3289 green, web build exit 0.

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

specs/STATE.md

@@ -1,6 +1,13 @@
 # VYNDR — STATE OF THE WORLD
 ### As of `a8e383e` (main, deployed + fingerprint-verified live), 2026-07-18. This file opens every future session. Update it when a train ships.
 
+## RARE-EVENT UNDER SUPPRESSION (2026-07-19, on main)
+Betting-logic audit: the CONSENSUS-vs-MODEL board flooded with "doubles u0.5 · MODEL 0.2 · +edge" fake reads (juiced rare-event unders). Report: the doubles projection is REAL per-player (MLB_LOG_FIELD doubles→doubles; values varied 0.03/0.16/0.2/0.22) — NOT a flat fallback; the issue is purely structural.
+- **Config-driven** (`src/config/rareEventMarkets.js`): RARE_EVENT_STATS = doubles/triples/home_runs/stolen_bases, RARE_EVENT_LINE_MAX = 0.5.
+- **Grade layer** (`analyzeViaEngine1`): rare-event UNDER at ≤0.5 → always refused (grade null + suppressed); rare-event OVER at ≤0.5 → refused unless projection > line (a 0.2-over-0.5 carries the SAME |edge| as the under, so it'd just take its board rank — refusing it is what actually clears the market). OVER with a genuine projection > line still grades.
+- **Board layer** (`marketBreadth.collectBreadth`): drops null-model rows — a suppressed/ungraded prop can't rank a "MODEL —" placeholder onto the board.
+- Suite 274/3289 green. Fingerprint: next MLB snapshot should have no rare-event u0.5 grades.
+
 ## BACKUP + FOUNDER CHECKOUT (2026-07-18, on main)
 - **Task A — DB backup (SHIPPED; Kev cron+fingerprint on box)** `c2c43cd`: Dockerfile now has pg_dump/pg_restore/rsync; `backup-db.sh` validates every dump via `pg_restore --list` (must contain ledger_entries). Runs IN the API container (SUPABASE_DB_URL is there; WSL2 can't reach Supabase). Runbook = host cron `docker exec <api> sh /app/scripts/backup-db.sh`. **Mechanism fingerprint PASSED locally** (137 rows → dump → validate → restore → 137 rows). Kev: install the host cron + run the prod restore fingerprint.
 - **Task B — founder checkout SEAT-GATED (SHIPPED)** `ccb9668`: `resolveCheckoutPrice` attaches the founder price while seats remain (< FOUNDER_SEATS_TOTAL, same `countFounderSeats()` truth as the meter), flips to standard at 100; meter shows SOLD OUT. Fixes "Claim a Founder Desk" charging $44.99 vs advertised $34.99. **payment_failed grace 48h→14d** (spans Stripe retries; revoke only on real cancel). Tested seat 0/99/100/null. Needs `STRIPE_PRICE_*_FOUNDER` set in prod for founder pricing to activate.