🔥(backend) remove the S3 storage-event webhook for recordings

Recordings used to be finalized by an inbound notifications sent by
S3. This tied the recording lifecycle to bucket notifications, adding
complexity and dependency to limited S3 services.

The LiveKit egress_ended webhook, added as a fallback in aee1847, does
the same job without any object-storage dependency. Make it the only
mechanism: RecordingEventsService.handle_complete is now called on
EGRESS_COMPLETE / EGRESS_LIMIT_REACHED unconditionally, instead of only
when RECORDING_STORAGE_EVENT_ENABLE is False. Remove the storage-event
path entirely.

src/backend/core/services/livekit_events.py

@@ -220,10 +220,8 @@ class LiveKitEventsService:
                     f"Failed to process limit reached event for recording {recording}"
                 ) from e
 
-        # Fallback for completion when no MinIO/S3 webhooks are configured
-        if (
-            not settings.RECORDING_STORAGE_EVENT_ENABLE
-        ) and data.egress_info.status in [
+        # Finalize the recording, the egress has uploaded the file to the storage
+        if data.egress_info.status in [
             api.EgressStatus.EGRESS_COMPLETE,
             api.EgressStatus.EGRESS_LIMIT_REACHED,
         ]: