feat(connection): ADB foreground fallback on the watchdog cadence when the protocol push is silent (store priority protocol > ADB); audio-playback hint filtered through SYSTEM_MEDIA_PACKAGES (P3-2b,c)

tests/test_connection.py

@@ -39,6 +39,8 @@ class FakePoller:
         self.sessions: list[MediaSessionInfo] = []
         self.apps: list[dict] = []
         self.audio_dump = ""
+        self.foreground: str | None = None
+        self.foreground_calls = 0
         self.head_lines_used: int | None = "unset"
 
     async def connect(self) -> bool:
@@ -76,6 +78,10 @@ class FakePoller:
     async def poll_running_apps(self) -> list[dict]:
         return list(self.apps)
 
+    async def poll_foreground(self) -> str | None:
+        self.foreground_calls += 1
+        return self.foreground
+
     async def send_media_command(self, command: str) -> bool:
         return self.connected