feat(bridge): add wifi/serial bridge runtime and UI

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_bridge_envelope.py

@@ -39,7 +39,7 @@ def test_unicast_mac_keys_per_device():
 def test_deliver_json_messages_defaults_broadcast():
     from util.driver_delivery import deliver_json_messages
 
-    class _Sender:
+    class _Bridge:
         def __init__(self):
             self.keys = []
 
@@ -49,14 +49,14 @@ def test_deliver_json_messages_defaults_broadcast():
             return True
 
     async def _run():
-        sender = _Sender()
+        bridge = _Bridge()
         await deliver_json_messages(
-            sender,
+            bridge,
             [json.dumps({"v": "1", "select": ["2"]})],
             ["188b0e1560a8", "e8f60a16ea10"],
             None,
         )
-        return sender.keys
+        return bridge.keys
 
     keys = __import__("asyncio").run(_run())
     assert keys == [BROADCAST_MAC]