CLV instrument repair: fix attachClosingProb read + recoverable market_unavailable

The closing_prob funnel collapsed 100k priced captures -> 59 usable. Root cause
(VERIFIED against prod, join key is PERFECT with 0 mismatches):
- attachClosingProb read closing_captures with .limit(50000) and NO ORDER BY on
  a 730k-row table that is 86% refusal rows -> saw ~7% for MLB, missed most
  priced closes and declared 200+ rows closeless that HAD a capture.
- market_unavailable_reason was write-once/terminal, so a row wrongly declared
  (truncated read / premature declaration before the capture was visible) could
  never recover even once its genuine capture existed. 298 rows (204 MLB + 94
  WNBA) were stuck this way.

Fix (CLV computation only — no grade/locked_odds/outcome touched):
- Read ONLY priced captures (missed_reason IS NULL, both odds NOT NULL), scoped
  to the candidate rows' game_dates -> small AND complete, no arbitrary truncation.
- Drop the market_unavailable exclusion from candidates; make it a re-checkable
  absence: a genuine close now UPGRADES the row (writes closing_prob, clears the
  verdict). closing_prob stays write-once (first true close wins). No capture +
  past game -> still declared absent (honest). No churn on already-absent rows.
- New internal trigger POST /api/internal/ledger/attach-closing[/:sport] for
  backfill + verification (scheduler already runs attach per tick).

Recovers ~312 usable closes (59 -> ~371), MLB included. Capture itself was
healthy all along (94.9% MLB / 95.8% WNBA per-prop coverage). Full suite 3835
green (17/17 instrument tests incl. 2 new recovery cases), web build exit 0.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VsztNChZ7vEvSR61AuMhD1

src/routes/internal.js

@@ -405,6 +405,33 @@ router.post('/ledger/settle', async (req, res) => {
   }
 });
 
+/**
+ * POST /api/internal/ledger/attach-closing[/:sport] — CLV instrument repair.
+ * Attach the de-vigged closing probability from `closing_captures` onto locked
+ * model-record rows. Recovers rows a truncated read / premature verdict wrongly
+ * declared closeless (market_unavailable is a re-checkable absence, not terminal).
+ * Idempotent: `closing_prob` is write-once; a row with a genuine close never
+ * changes, and a row with no capture stays honestly absent.
+ */
+async function attachClosingHandler(req, res) {
+  const ledger = require('../services/ledgerService');
+  const ALL = ['mlb', 'wnba', 'nba', 'soccer'];
+  const only = String(req.params.sport || '').toLowerCase();
+  const sports = only ? [only] : ALL;
+  try {
+    const results = {};
+    for (const sp of sports) results[sp] = await ledger.attachClosingProb(sp, { limit: Number(req.query.limit) || undefined });
+    return res.json({ ok: true, results });
+  } catch (err) {
+    const message = err && err.message ? err.message : String(err);
+    console.error('[internal/ledger/attach-closing] failed:', message);
+    return res.status(500).json({ ok: false, error: message });
+  }
+}
+// Express 5 (path-to-regexp v8) has no `/:sport?` optional param — register both.
+router.post('/ledger/attach-closing', attachClosingHandler);
+router.post('/ledger/attach-closing/:sport', attachClosingHandler);
+
 /**
  * POST /api/internal/newsletter/send (Session S7, a1) — assemble today's
  * VYNDR REPORT from the pipeline (snapshot signals + streak lens + the