fix: add cleanup methods to protocol interface

Fixes mypy errors by adding cleanup_old_recordings and
cleanup_recordings_loop to AmcrestServiceProtocol.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/amcrest2mqtt/interface.py

@@ -46,6 +46,8 @@ class AmcrestServiceProtocol(Protocol):
     async def build_device_states(self, device_id: str) -> bool: ...
     async def check_event_queue_loop(self) -> None: ...
     async def check_for_events(self) -> None: ...
+    async def cleanup_old_recordings(self) -> None: ...
+    async def cleanup_recordings_loop(self) -> None: ...
     async def collect_all_device_events(self) -> None: ...
     async def collect_all_device_snapshots(self) -> None: ...
     async def collect_events_loop(self) -> None: ...