Refresh `BluetoothDevice.reachable` when a device is found/lost.

platypush/plugins/bluetooth/_ble/_event_handler.py

@@ -183,6 +183,7 @@ class EventHandler:
             get_bus().post(event)
 
         if events:
+            new_entity.reachable = True
             self._device_queue.put_nowait(new_entity)
 
     @staticmethod

platypush/plugins/bluetooth/_cache.py

@@ -176,6 +176,10 @@ class EntityCache(BaseCache):
             if getattr(existing_device, attr, None) is None:
                 setattr(existing_device, attr, getattr(device, attr, None))
 
+        # Coalesce the reachable flag
+        if device.reachable is not None:
+            existing_device.reachable = device.reachable
+
         # Merge the data and meta dictionaries
         for attr in ('data', 'meta'):
             setattr(