feat: entry.runtime_data ShieldConnectionManager lifecycle — passive when ADB unavailable, close on HA stop + unload; adb_session adapter docstring

custom_components/nvidia_shield/connection.py

@@ -115,6 +115,21 @@ class ShieldConnectionManager:
         self._failures = 0
         self._down_since = False  # listeners already told the connection is down
 
+    # ── One-shot connection test (pairing UX) ──
+
+    @staticmethod
+    async def test_connect(host: str, port: int, key_path: str) -> bool:
+        """Single-shot ADB connect used by the config-flow pairing step.
+
+        Throws away the poller immediately — the config flow runs before any
+        entry exists, so it must never touch an entry's persistent socket.
+        """
+        poller = AdbMediaSessionPoller(host, port, key_path)
+        try:
+            return await poller.connect()
+        finally:
+            await poller.disconnect()
+
     # ── Introspection (thin views for entities) ──
 
     @property