♻️(backend) pass the participant role in the LiveKit token

The backend previously passed an abstract is_admin_or_owner boolean
flag in the LiveKit token. That kept the frontend minimalistic and
saved it from having to handle role comparisons.

As we introduce more features that need to distinguish between the
room owner and admins, refactor the token to carry the role
directly. The frontend can then derive the relevant flags from a
richer piece of information.

src/backend/core/services/lobby.py

@@ -104,21 +104,30 @@ class LobbyService:
             )
 
     @staticmethod
-    def can_bypass_lobby(room, user) -> bool:
+    def can_bypass_lobby(room, user, role) -> bool:
         """Determines if a user can bypass the waiting lobby and join a room directly.
 
         A user can bypass the lobby if:
         1. The room is public (open to everyone)
         2. The room has TRUSTED access level and the user is authenticated
+        2. The room has RESTRICTED access level and the user has any role
 
         Note: Room access levels can change while participants are waiting in the lobby.
         This function only checks the current state and should be called each time
         a participant requests entry to ensure consistent access control, even for
         participants who have already begun waiting.
         """
-        return room.is_public or (
-            room.access_level == models.RoomAccessLevel.TRUSTED
-            and user.is_authenticated
+        return (
+            room.is_public
+            or (
+                room.access_level == models.RoomAccessLevel.TRUSTED
+                and user.is_authenticated
+            )
+            or (
+                room.access_level == models.RoomAccessLevel.RESTRICTED
+                and user.is_authenticated
+                and role is not None
+            )
         )
 
     def request_entry(
@@ -144,8 +153,9 @@ class LobbyService:
         participant = self._get_participant(room.id, participant_id)
 
         room_id = str(room.id)
+        user_role = room.get_role(request.user)
 
-        if self.can_bypass_lobby(room=room, user=request.user):
+        if self.can_bypass_lobby(room=room, user=request.user, role=user_role):
             if participant is None:
                 participant = LobbyParticipant(
                     status=LobbyParticipantStatus.ACCEPTED,
@@ -162,8 +172,8 @@ class LobbyService:
                 username=username,
                 color=participant.color,
                 configuration=room.configuration,
-                is_admin_or_owner=False,
                 participant_id=participant_id,
+                role=user_role,
             )
             return participant, livekit_config
 
@@ -183,8 +193,8 @@ class LobbyService:
                 username=username,
                 color=participant.color,
                 configuration=room.configuration,
-                is_admin_or_owner=False,
                 participant_id=participant_id,
+                role=user_role,
             )
 
         return participant, livekit_config