Validate and persist API chat lifetime: lifetime_hours is validated as a positive number and stored in the AgentContext data, and context.last_message is set using UTC. Removed the in-class threading-based cleanup state and old _cleanup_expired_chats method. Introduced a new job-loop extension (extensions/python/job_loop/_20_cleanup_expired_api_chats.py) that periodically scans AgentContext instances and removes expired API chats (using persist_chat.remove_chat) in a UTC-aware manner. Added tests (tests/test_api_chat_lifetime.py) to verify lifetime persistence and that the job loop removes expired chats.
- Add `watchdog` dependency to requirements.txt
- Implement cache entry timestamps with `CacheEntry` dataclass for LRU-style tracking
- Add `trim_cache` function to remove stale entries based on age
- Update cache operations to track and update entry timestamps on access
- Add `_get_matching_areas` helper for wildcard pattern matching in cache clearing
- Register watchdogs for API handlers, extensions, and plugins to
