feat: coordinate authoritative playback and audio routing

tests/test_config_contracts.py

@@ -29,6 +29,7 @@ class ContractCharacterizationTests(unittest.TestCase):
         self.assertEqual(topics.playback_base, "youtube/media/playback")
         self.assertEqual(topics.router_mode_set, "audio/player/mode/set")
         self.assertEqual(topics.router_mode_state, "audio/player/mode/state")
+        self.assertEqual(topics.controller_result, "youtube/controller/v2/events")
         self.assertEqual(PLAYER_COMMAND_QOS, 1)
         self.assertIs(PLAYER_COMMAND_RETAIN, False)
         self.assertEqual(SLOT_IDS, tuple(range(1, 11)))
@@ -79,6 +80,7 @@ class ConfigurationTests(unittest.TestCase):
         self.assertIs(config.router.continue_on_confirmation_failure, True)
         self.assertIsNone(config.router.fallback_restore_mode)
         self.assertEqual(config.storage.uncertain_review_after_seconds, 900.0)
+        self.assertEqual(config.mqtt.publish_ack_timeout_seconds, 2.0)
 
     def test_documented_environment_overrides_apply(self):
         env = {