feat: remove unjoined sub-room handling from Home and Space components

src/app/pages/client/space/Space.tsx

@@ -470,9 +470,6 @@ export function Space() {
           items.push({ type: 'subroom', roomId: subRoomId, room: subRoom, depth: baseDepth + 1, isLast });
           // Recursively add sub-rooms of sub-rooms
           addSubRooms(subRoomId, baseDepth + 1);
-        } else {
-          // Unjoined sub-room - show with join button
-          items.push({ type: 'unjoined-subroom', roomId: subRoomId, depth: baseDepth + 1, isLast });
         }
       });
     };