feat: Multitrack segmentation (#747)

* segmentation multitrack (no-mistakes)

* segmentation multitrack (no-mistakes)

* self review

* self review

* recording poll daily doc

* filter cam_audio tracks to remove screensharing from daily processing

* pr review

---------

Co-authored-by: Igor Loskutov <igor.loskutoff@gmail.com>

server/reflector/db/recordings.py

@@ -35,8 +35,15 @@ class Recording(BaseModel):
     status: Literal["pending", "processing", "completed", "failed"] = "pending"
     meeting_id: str | None = None
     # for multitrack reprocessing
+    # track_keys can be empty list [] if recording finished but no audio was captured (silence/muted)
+    # None means not a multitrack recording, [] means multitrack with no tracks
     track_keys: list[str] | None = None
 
+    @property
+    def is_multitrack(self) -> bool:
+        """True if recording has separate audio tracks (1+ tracks counts as multitrack)."""
+        return self.track_keys is not None and len(self.track_keys) > 0
+
 
 class RecordingController:
     async def create(self, recording: Recording):