feat: protocol key/launch command layer — RemoteKeyCode maps, C-LAUNCH app launch, ADB digit keyevent fallback, PlaybackIntent protocol path

custom_components/nvidia_shield/ha_adb_common/intent.py

@@ -22,8 +22,11 @@ class PlaybackIntent:
             the remote that did not serve it.
         adb_command: The ADB keycode command name matching the intent
             (play/pause/stop/next/previous); set together with via_adb.
+        via_protocol: True when the command was served by the remote-protocol
+            key push (Phase 2) — the retry then goes over the protocol key
+            again instead of the other transports.
+        protocol_key: The protocol keycode string served with via_protocol.
     """
-
     target_state: str  # MediaPlayerState value (e.g. "playing", "paused")
     command: str
     created_at: float
@@ -31,6 +34,8 @@ class PlaybackIntent:
     retry_count: int = 0
     via_adb: bool = False
     adb_command: str | None = None
+    via_protocol: bool = False
+    protocol_key: str | None = None
 
     @classmethod
     def create(