🎨(backend) use object primary key instead of id attribute

Replace id attribute references with object primary key for better code
consistency and Django model conventions.

requested by @qbey

src/backend/core/api/viewsets.py

@@ -584,7 +584,7 @@ class RoomViewSet(
 
         try:
             ParticipantsManagement().mute(
-                room_name=str(room.id),
+                room_name=str(room.pk),
                 identity=str(serializer.validated_data["participant_identity"]),
                 track_sid=serializer.validated_data["track_sid"],
             )
@@ -617,7 +617,7 @@ class RoomViewSet(
 
         try:
             ParticipantsManagement().update(
-                room_name=str(room.id),
+                room_name=str(room.pk),
                 identity=str(serializer.validated_data["participant_identity"]),
                 metadata=serializer.validated_data.get("metadata"),
                 attributes=serializer.validated_data.get("attributes"),
@@ -653,7 +653,7 @@ class RoomViewSet(
 
         try:
             ParticipantsManagement().remove(
-                room_name=str(room.id),
+                room_name=str(room.pk),
                 identity=str(serializer.validated_data["participant_identity"]),
             )
         except ParticipantsManagementException:

src/backend/core/services/telephony.py

@@ -38,12 +38,12 @@ class TelephonyService:
 
         direct_rule = SIPDispatchRule(
             dispatch_rule_direct=SIPDispatchRuleDirect(
-                room_name=str(room.id), pin=str(room.pin_code)
+                room_name=str(room.pk), pin=str(room.pin_code)
             )
         )
 
         request = CreateSIPDispatchRuleRequest(
-            rule=direct_rule, name=self._rule_name(room.id)
+            rule=direct_rule, name=self._rule_name(room.pk)
         )
 
         lkapi = utils.create_livekit_client()

src/backend/core/tests/services/test_lobby.py

@@ -450,7 +450,7 @@ def test_enter_success(
         timeout=settings.LOBBY_WAITING_TIMEOUT,
     )
     mock_notify.assert_called_once_with(
-        room_name=str(room.id), notification_data={"type": "participantWaiting"}
+        room_name=str(room.pk), notification_data={"type": "participantWaiting"}
     )