feat: Subscribe to PropertiesChanged for dynamic device naming

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

scan.py

@@ -55,8 +55,39 @@ def on_interfaces_added(path, interfaces):
                 # Log repeat discoveries only if they have a name
                 logging.info(f"Found: {alias} ({addr_str})")
 
+async def on_properties_changed(message: Message):
+    """Callback for when a device's properties change (e.g., Alias appears)."""
+    if not message.body or message.body[0] != DEVICE_IFACE:
+        return
+
+    changed_properties = message.body[1]
+    alias_variant = changed_properties.get('Alias')
+    if not alias_variant or not alias_variant.value:
+        return
+
+    alias = alias_variant.value
+    device_path = message.path
+
+    try:
+        introspection = await bus.introspect(BLUEZ_SERVICE, device_path)
+        device_obj = bus.get_proxy_object(BLUEZ_SERVICE, device_path, introspection)
+        device_props_iface = device_obj.get_interface('org.freedesktop.DBus.Properties')
+        
+        address_variant = await device_props_iface.call_get(DEVICE_IFACE, 'Address')
+        addr_str = address_variant.value
+
+        # Update cache
+        name_cache[addr_str] = alias
+
+        if addr_str not in seen_devices:
+            seen_devices.add(addr_str)
+            logging.info(f"Found: {alias} ({addr_str}) (new)")
+    except Exception as e:
+        logging.debug(f"Could not process property change for {device_path}: {e}")
+
 async def main():
     """Main function to run the scanner."""
+    global bus
     bus = await MessageBus(bus_type=BusType.SYSTEM).connect()
     adapter = await get_adapter(bus)
     if not adapter:
@@ -71,6 +102,14 @@ async def main():
     obj_manager_iface = obj_manager.get_interface('org.freedesktop.DBus.ObjectManager')
     obj_manager_iface.on_interfaces_added(on_interfaces_added)
 
+    # Subscribe to PropertiesChanged signal to catch late-arriving device names
+    bus.add_signal_receiver(
+        on_properties_changed,
+        signal_name='PropertiesChanged',
+        dbus_namespace='org.freedesktop.DBus.Properties',
+        path_namespace='/org/bluez'
+    )
+
     logging.info("Starting Bluetooth scan... Press Ctrl+C to stop.")
     try:
         await adapter_iface.call_start_discovery()