fix(recording): handle unexpected filenames in cache maintainer to prevent crash (#21676)

* fix(recording): handle unexpected filenames in cache maintainer to prevent crash

* test(recording): add test for maintainer cache file parsing

* Prevent log spam from unexpected cache files

Addresses PR review feedback: Add deduplication to prevent warning
messages from being logged repeatedly for the same unexpected file
in the cache directory. Each unexpected filename is only logged once
per RecordingMaintainer instance lifecycle.

Also adds test to verify warning is only emitted once per filename.

* Fix code formatting for test_maintainer.py

* fixes + ruff

frigate/record/maintainer.py

@@ -97,6 +97,7 @@ class RecordingMaintainer(threading.Thread):
         self.object_recordings_info: dict[str, list] = defaultdict(list)
         self.audio_recordings_info: dict[str, list] = defaultdict(list)
         self.end_time_cache: dict[str, Tuple[datetime.datetime, float]] = {}
+        self.unexpected_cache_files_logged: bool = False
 
     async def move_files(self) -> None:
         cache_files = [
@@ -112,7 +113,14 @@ class RecordingMaintainer(threading.Thread):
         for cache in cache_files:
             cache_path = os.path.join(CACHE_DIR, cache)
             basename = os.path.splitext(cache)[0]
-            camera, date = basename.rsplit("@", maxsplit=1)
+            try:
+                camera, date = basename.rsplit("@", maxsplit=1)
+            except ValueError:
+                if not self.unexpected_cache_files_logged:
+                    logger.warning("Skipping unexpected files in cache")
+                    self.unexpected_cache_files_logged = True
+                continue
+
             start_time = datetime.datetime.strptime(
                 date, CACHE_SEGMENT_FORMAT
             ).astimezone(datetime.timezone.utc)
@@ -164,7 +172,13 @@ class RecordingMaintainer(threading.Thread):
 
             cache_path = os.path.join(CACHE_DIR, cache)
             basename = os.path.splitext(cache)[0]
-            camera, date = basename.rsplit("@", maxsplit=1)
+            try:
+                camera, date = basename.rsplit("@", maxsplit=1)
+            except ValueError:
+                if not self.unexpected_cache_files_logged:
+                    logger.warning("Skipping unexpected files in cache")
+                    self.unexpected_cache_files_logged = True
+                continue
 
             # important that start_time is utc because recordings are stored and compared in utc
             start_time = datetime.datetime.strptime(