zhuzhh fe928a0d94 feat(msteams): split ref storage into main+meta sidecar files
- Separate updated_at into a meta sidecar file (msteams_conversations_meta.json)
    to keep backward compatibility with legacy data that never had updated_at.
    On first upgrade, legacy refs are kept alive by initializing updated_at to now
    instead of purging them immediately.
  - Add cross-process locking via fcntl (with Windows fallback) to prevent
    concurrent writes from different gateway processes overwriting each other.
  - Add ref_touch_interval_s config (default 300s) to throttle how often
    successful sends refresh updated_at, preventing unnecessary I/O.
  - Touch active refs on send success to prevent them from expiring while in use.
  - Add _safe_float and _normalize_ref_record for robust schema migration.
  - All refs operations now use threading.RLock within a process.
2026-04-25 15:39:43 +08:00
..