fix: add destroy() and signal cleanup across widgets, fix settings window + menu regressions

P0 leak fixes: context/action menus destroyed on deactivate, config
callbacks unregistered in settings widgets, recorder and server signal
IDs stored and disconnected, bluetooth client closed and unsubscribed,
rfkill timer removed, seek timers cancelled, dropdown and options menus
freed, app name cache LRU-bounded.

Fix desktop 'Edit Widgets' and settings menu regressions by deferring
destroy out of Gtk signal handlers via GLib.idle_add.

Fix settings entry fields by connecting the activate signal explicitly
(Enter saves the value).

src/window/settings/main.py

@@ -1,4 +1,4 @@
-from fabric.utils import Gdk, Gtk
+from fabric.utils import Gdk, GLib, Gtk
 from fabric.widgets.box import Box
 from fabric.widgets.button import Button
 from fabric.widgets.centerbox import CenterBox
@@ -7,7 +7,7 @@ from fabric.widgets.label import Label
 from fabric.widgets.scrolledwindow import ScrolledWindow
 from fabric.widgets.stack import Stack
 
-from services.config import config, on_config_change
+from services.config import config, off_config_change, on_config_change
 from shared.widgets.smooth_switch import SmoothSwitch
 from utils.gtk_utils import setup_cursor_hover, svg_file
 
@@ -66,6 +66,10 @@ class SettingsSwitch(SmoothSwitch):
         config().set(self.config_key, state)
         config().save()
 
+    def destroy(self):
+        off_config_change(self._on_config_change)
+        super().destroy()
+
 
 class SettingsEntry(Entry):
     def __init__(self, config_key: str, **kwargs):
@@ -75,9 +79,9 @@ class SettingsEntry(Entry):
         super().__init__(
             name="settings-entry",
             text=initial_value,
-            on_activate=self.on_change,
             **kwargs,
         )
+        self.connect("activate", self.on_change)
 
         # Sync with external config changes
         on_config_change(self._on_config_change)
@@ -101,6 +105,10 @@ class SettingsEntry(Entry):
         config().set(self.config_key, value)
         config().save()
 
+    def destroy(self):
+        off_config_change(self._on_config_change)
+        super().destroy()
+
 
 class SettingsComboBox(Gtk.ComboBoxText):
     def __init__(self, config_key: str, options: list, **kwargs):
@@ -134,6 +142,10 @@ class SettingsComboBox(Gtk.ComboBoxText):
             config().set(self.config_key, value)
             config().save()
 
+    def destroy(self):
+        off_config_change(self._on_config_change)
+        super().destroy()
+
 
 class SettingsList(Box):
     """A list of tags that can be added or removed"""
@@ -146,8 +158,8 @@ class SettingsList(Box):
         self.entry = Entry(
             name="settings-list-entry",
             placeholder="Add new item...",
-            on_activate=self.on_add,
         )
+        self.entry.connect("activate", self.on_add)
 
         self.add(self.list_box)
         self.add(self.entry)
@@ -206,6 +218,10 @@ class SettingsList(Box):
             config().save()
         self._update_list()
 
+    def destroy(self):
+        off_config_change(self._on_config_change)
+        super().destroy()
+
 
 class SettingsPage(ScrolledWindow):
     def __init__(self, title: str, rows: list, **kwargs):
@@ -246,8 +262,11 @@ class SettingsWindow(Gtk.Window):
         self.set_position(Gtk.WindowPosition.CENTER)
         self.set_visible(False)
 
-        # Hide instead of destroy so the __main__ reference stays valid
-        self.connect("delete-event", lambda *_: self.hide() or True)
+        # Destroy on close so the widget tree is freed; get_settings_window
+        # recreates it on next open. Destruction is deferred out of the
+        # delete-event emission to avoid tearing the window down mid-signal.
+        self.connect("delete-event", self._on_delete_event)
+        self.connect("destroy", self._on_window_destroyed)
 
         self.stack = Stack(
             name="settings-stack",
@@ -508,6 +527,11 @@ class SettingsWindow(Gtk.Window):
         )
 
     def toggle(self):
+        if getattr(self, "_destroyed", False):
+            # A stale reference (e.g. __main__.settings) outlived this window.
+            get_settings_window().toggle()
+            return
+
         if not self.get_visible():
             self.show_all()
             self.present()
@@ -522,6 +546,16 @@ class SettingsWindow(Gtk.Window):
         else:
             self.hide()
 
+    def _on_delete_event(self, *_):
+        GLib.idle_add(self.destroy)
+        return True
+
+    def _on_window_destroyed(self, *_):
+        global _settings_window
+        self._destroyed = True
+        if _settings_window is self:
+            _settings_window = None
+
 
 _settings_window = None