feat: Automatically remove devices unpaired by remote host

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

main.py

@@ -158,6 +158,32 @@ async def set_adapter_alias(alias):
     except Exception as e:
         logging.error(f"Failed to set adapter alias: {e}")
 
+async def monitor_unpairing():
+    logging.info("Starting to monitor for device unpairing events.")
+    adapter_obj = await get_adapter()
+    if not adapter_obj:
+        logging.error("Bluetooth adapter not found, cannot monitor unpairing.")
+        return
+
+    adapter_iface = adapter_obj.get_interface(ADAPTER_IFACE)
+
+    def _properties_changed_handler(interface_name, changed_properties, invalidated_properties, msg):
+        if interface_name == DEVICE_IFACE and 'Paired' in changed_properties and not changed_properties['Paired'].value:
+            device_path = msg.path
+            logging.info(f"Device {device_path} was unpaired by the remote host. Removing it.")
+            asyncio.create_task(adapter_iface.call_remove_device(device_path))
+
+    bus.add_signal_receiver(
+        _properties_changed_handler,
+        signal_name='PropertiesChanged',
+        dbus_interface='org.freedesktop.DBus.Properties',
+        path_namespace='/org/bluez'
+    )
+    
+    # Keep the task alive to listen for signals
+    while True:
+        await asyncio.sleep(3600)
+
 # --- End Bluetooth ---
 
 async def manage_bluetooth():
@@ -225,7 +251,8 @@ async def main():
 
     manage_task = asyncio.create_task(manage_bluetooth())
     mqtt_task = asyncio.create_task(fetch_mqtt())
-    await asyncio.gather(manage_task, mqtt_task)
+    unpair_task = asyncio.create_task(monitor_unpairing())
+    await asyncio.gather(manage_task, mqtt_task, unpair_task)
 
 
 if __name__ == '__main__':