Session A (night2): AUTONOMY.md + SNAP_TTL 6h→24h P0 fix

The overnight cron gap (03→14 UTC) is 11h; a 6h snapshot TTL meant the
morning settle pass read an expired snapshot and the accuracy loop
silently settled nothing. Ledger (Postgres) settle was immune.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/services/snapshotService.js

@@ -17,7 +17,11 @@
  *   ticker:items               — capped array of ticker events (newest first)
  */
 
-const SNAP_TTL = 6 * 3600;      // 6h — a snapshot is valid until the next run
+// Session 60 (AUTONOMY P0) — 24h, NOT 6h. The overnight cron gap is 11 hours
+// (03:00 UTC → 14:00 UTC); with a 6h TTL the morning settle pass read an
+// EXPIRED snapshot and the accuracy loop silently settled nothing. The
+// snapshot must survive until the morning-after settle reads it.
+const SNAP_TTL = 24 * 3600;
 const TICKER_TTL = 24 * 3600;
 const TICKER_CAP = 50;
 const DELTA_NOISE = 0.5;        // ignore movements smaller than this