Add filtering methods to JsonFileRoomStorage for Phase 2 soft delete support:
- list_bounties(room_id): returns only non-deleted bounties for normal queries
- list_all_bounties(room_id, include_deleted=True): returns all bounties for /recover
Update RoomStorage protocol to include the new methods.
Update mock classes in tests to pass isinstance checks.
Fixes#42
Tests with SimpleRoomStorage and SimpleTrackingStorage (without ensure_*)
show that add_bounty() and track_bounty() work fine without explicit
ensure methods - they create rooms/tracking internally.
This simplifies the Protocol to only essential methods.
- Removed PersonalStorage (redundant - RoomStorage handles both via room_id)
- Added ensure_room() and ensure_tracking() methods for explicit creation
- Added @runtime_checkable to Protocols for isinstance checks
- Added tests/test_ports.py with 11 unit tests for storage protocols
