v0.2.0 — gate-hardening

failclosed v0.2.0 — gate-hardening

Two latent fail-open paths closed — a merge could report MERGE_READY while a
real, unresolved review signal was still open, the exact failure class failclosed
exists to prevent — plus reviewer-format currency and idempotent thread resolution.

Fixed

• Codex reviewer threads are no longer dropped. The GitHub Codex reviewer
  (chatgpt-codex-connector) is now recognized, so its unresolved threads are
  counted before the gate decides. Previously the gate could clear with an open
  Codex P1 thread.
• The receipt classifier is fail-closed by construction. A pathless review
  thread auto-resolves only when, after carving out the receipt phrase, no content
  remains — Unicode-aware and NFKC-normalized. A real finding that merely opens
  with "No findings…", in any language or disguised with homoglyphs, keeps the
  thread open. (A denylist of weak words / continuation markers is unbounded-
  bypassable; this inverts to a pure-receipt check.)

Added

• Parser currency for codex CLI ≥0.13x native review ([P0–P3] markers +
  trailing em-dash path:start-end).
• Idempotent reply/resolve — re-checks live thread state and skips a duplicate
  reply on a partial-failure retry; best-effort probes never suppress the resolve.

Full notes in CHANGELOG.md. 59 tests; ruff + leak gate clean.