Restart from the tree no longer hangs for 30 s on disconnect

With a wiresheet open, disconnecting first unsubscribed its components and
waited for the reply, which a restarting device never sends, so the editor
froze until the request timed out. After restart, reboot, quit or hibernate
the session is now closed without asking the device anything; a plain
Disconnect still unsubscribes first.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app_state.py

@@ -8,7 +8,7 @@ so later rebinding would only ever be seen by the module that did it.
 import configparser
 import os
 
-VERSION = "0.0.0.168"
+VERSION = "0.0.0.169"
 PROPERTIES_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "editor.properties")
 DEFAULT_GRID_SIZE = 10
 DEFAULT_ADD_TIMESTAMP = True

device_session.py

@@ -60,11 +60,13 @@ class DeviceSession:
                 self.sox_client.update(children, CONFIG | RUNTIME)
         return root_comp
 
-    def disconnect(self):
+    def disconnect(self, unsubscribe=True):
+        """Closes the session. unsubscribe=False skips telling the device first -- for a
+        device going down, which would leave the request to time out."""
         if self.sox_client is None:
             return
         try:
-            if self._current_subs:
+            if unsubscribe and self._current_subs:
                 comps = [self.sox_client.cache_get(cid)
                          for cid in self._current_subs]
                 comps = [c for c in comps if c is not None]

main.py

@@ -636,7 +636,7 @@ def _invoke_app_action(slot_name):
         app_state.set_status(f"Invoked '{slot_name}' on device")
     elif goes_down:
         host = app_state.device_host
-        do_device_disconnect()
+        do_device_disconnect(device_down=True)
         app_state.set_status(f"Sent '{slot_name}' to {host} and disconnected")
     else:
         app_state.set_status(f"Invoked '{slot_name}' on device")
@@ -2996,8 +2996,9 @@ def _load_live_schema(ds):
             f"Missing kit manifests: {', '.join(missing)}", warn=True)
 
 
-def do_device_disconnect():
-    """Disconnects from the live device."""
+def do_device_disconnect(device_down=False):
+    """Disconnects from the live device. device_down: it was just told to restart (or
+    stop), so nothing is asked of it on the way out -- it would not answer."""
     global _cov_poll_id
 
     if _cov_poll_id is not None:
@@ -3006,7 +3007,7 @@ def do_device_disconnect():
 
     ds = app_state.device_session
     if ds is not None:
-        ds.disconnect()
+        ds.disconnect(unsubscribe=not device_down)
 
     app_state.device_session = None
     app_state.live_mode = False