research: data-moat hardening — durable settle logs, offline-proof forward backfill, nightly market-metadata snapshot

- surgebot/oraclebot: settles now append-only to /data/*_settles.jsonl
  (SETTLED_TRIM rotation can never lose a settle; graders pull them)
- forward.py: backfills any tape-covered day missing from the ledger —
  a Mac offline gap > RESCORE_DAYS no longer leaves verdict-evidence holes
- meta_snap.py: nightly gzipped snapshot of all active markets (12k, 2MB/d,
  local-only) — end dates make tau knowable at trigger for every tape
  trigger; token->outcome maps kill the label-gap scorer artifact class
- .gitignore: pulled raw streams + meta stay local (re-fetchable, lean repo)

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

research/nightly.sh

@@ -55,6 +55,7 @@ done
 "$PY" grade_surge.py >> forward.log 2>&1 || true   # A2 measurement -> chain truth
 "$PY" surge_book_replay.py >> forward.log 2>&1 || true  # virtual $100/5% book
 "$PY" grade_oracle.py >> forward.log 2>&1 || true  # oracle paper -> chain truth
+"$PY" meta_snap.py >> forward.log 2>&1 || true     # market metadata (local gz)
 
 cd ..
 git add research/forward_ledger.jsonl research/params/informed_set.json \