fix(logs): let the View Logs dialog close via titlebar-X (#892)

* fix(logs): let the View Logs dialog close via titlebar-X

_on_response only destroyed on ResponseType.CLOSE and ignored
DELETE_EVENT, so the Logs window could not be dismissed with the
window-manager close button — unlike Settings, which handles both. A
window force-destroyed behind the dialog then crashed quit with a
BadWindow error instead of an orderly shutdown.

* test(logs): cover _on_response behavior; annotate its signature

---------

Co-authored-by: Jatin K Malik <jatinkrmalik@gmail.com>

src/vocalinux/ui/logging_dialog.py

@@ -622,9 +622,9 @@ class LoggingDialog(Gtk.Dialog):
 
         return False  # Remove from idle queue
 
-    def _on_response(self, dialog, response_id):
+    def _on_response(self, dialog: Gtk.Dialog, response_id: int) -> None:
         """Handle dialog responses."""
-        if response_id == Gtk.ResponseType.CLOSE:
+        if response_id in (Gtk.ResponseType.CLOSE, Gtk.ResponseType.DELETE_EVENT):
             self.destroy()
 
     def _export_logs(self):