test: add /bridge/rooms endpoint tests — room listing, occupant counts, empty state

tests/test_multi_user_bridge.py

@@ -364,3 +364,36 @@ class TestRoomBroadcast:
         c, _ = client
         resp = await c.get("/bridge/room_events/nonexistent")
         assert resp.status == 404
+
+    @pytest.mark.asyncio
+    async def test_rooms_lists_all_rooms_with_occupants(self, client):
+        c, bridge = client
+        await c.post("/bridge/chat", json={
+            "user_id": "alice", "username": "Alice", "message": "hi", "room": "Tower"
+        })
+        await c.post("/bridge/chat", json={
+            "user_id": "bob", "username": "Bob", "message": "hi", "room": "Tower"
+        })
+        await c.post("/bridge/chat", json={
+            "user_id": "carol", "username": "Carol", "message": "hi", "room": "Library"
+        })
+        resp = await c.get("/bridge/rooms")
+        assert resp.status == 200
+        data = await resp.json()
+        assert data["total_rooms"] == 2
+        assert data["total_users"] == 3
+        assert "Tower" in data["rooms"]
+        assert "Library" in data["rooms"]
+        assert data["rooms"]["Tower"]["count"] == 2
+        assert data["rooms"]["Library"]["count"] == 1
+        tower_users = {o["user_id"] for o in data["rooms"]["Tower"]["occupants"]}
+        assert tower_users == {"alice", "bob"}
+
+    @pytest.mark.asyncio
+    async def test_rooms_empty_when_no_sessions(self, client):
+        c, _ = client
+        resp = await c.get("/bridge/rooms")
+        data = await resp.json()
+        assert data["total_rooms"] == 0
+        assert data["total_users"] == 0
+        assert data["rooms"] == {}