- Refactor FirestoreNotificationBackend to use time-gated window
(window_hours) instead of notified_by_agent status filtering;
mark_as_notified is now a no-op (agent is awareness-only).
- Update agent.py to instantiate FirestoreNotificationBackend using the
shared firestore_db client instead of RedisNotificationBackend.
- Remove redis_host/redis_port settings from config.py; add
notifications_collection_path, max_to_notify, and window_hours.
- Move redis/json imports inside RedisNotificationBackend methods so
redis is only required if that backend is explicitly instantiated.
- Add utility scripts for checking and registering notifications.
- Add google-cloud-firestore dependency to pyproject.toml.