🐛(backend) preserve recording metadata when updating room access

Updating room access rewrote the entire metadata payload, removing information
about active recordings. This caused the frontend to lose track of ongoing
recordings and could trigger 409 errors when attempting to start a new
recording.

Consolidate the duplicated metadata update logic into
`RoomManagement.update_metadata()` and preserve merge behavior instead of
overwriting the full metadata object.

src/backend/core/recording/services/recording_events.py

@@ -9,6 +9,11 @@ from livekit import api
 from core import models, utils
 from core.models import Recording
 from core.recording.event.notification import notification_service
+from core.services.room_management import (
+    RoomManagement,
+    RoomManagementException,
+    RoomNotFoundException,
+)
 
 logger = getLogger(__name__)
 
@@ -39,10 +44,15 @@ class RecordingEventsService:
         recording_status = status_mapping.get(egress_status)
         if recording_status:
             try:
-                utils.update_room_metadata(
+                RoomManagement().update_metadata(
                     room_name, {"recording_status": recording_status}
                 )
-            except utils.MetadataUpdateException as e:
+            except RoomNotFoundException:
+                logger.info(
+                    "LiveKit room %s no longer exists, skipping metadata update",
+                    room_name,
+                )
+            except RoomManagementException as e:
                 logger.exception("Failed to update room's metadata: %s", e)
 
     @staticmethod

src/backend/core/recording/worker/mediator.py

@@ -2,8 +2,12 @@
 
 import logging
 
-from core import utils
 from core.models import Recording, RecordingStatusChoices
+from core.services.room_management import (
+    RoomManagement,
+    RoomManagementException,
+    RoomNotFoundException,
+)
 
 from .exceptions import (
     RecordingStartError,
@@ -64,10 +68,15 @@ class WorkerServiceMediator:
         mode = recording.options.get("original_mode", None) or recording.mode
 
         try:
-            utils.update_room_metadata(
+            RoomManagement().update_metadata(
                 room_name, {"recording_mode": mode, "recording_status": "starting"}
             )
-        except utils.MetadataUpdateException as e:
+        except RoomNotFoundException:
+            logger.info(
+                "LiveKit room %s no longer exists, skipping metadata update",
+                room_name,
+            )
+        except RoomManagementException as e:
             logger.exception("Failed to update room's metadata: %s", e)
 
         logger.info(