fix: add bounded Antigravity local token history (#3212)

Add bounded token-only history from recognized Antigravity SQLite and JSONL sources. Preserve exact counters, source completeness, session identity, cancellation and read-only database semantics through the existing shared publication and presentation owners.

Include the maintainer-owned Gemini readiness-fixture follow-up without changing production timeouts or retry policy.

Co-authored-by: Yuxin Qiao <104957188+Yuxin-Qiao@users.noreply.github.com>