Add a searchable /config preferences panel to the TUI (#52990)

## What changed

- Group preferences into Appearance, Notifications, Input, Sessions, and Text selection tabs, with search and links to existing theme, status line, terminal title, and keyboard editors.
- Persist preference changes to the selected local configuration file, apply supported changes immediately, and show save errors, configuration overrides, and restart requirements in the panel.
- Add a delayed notification test and controls for notification timing while preserving custom event filters.
- Add `tui.copy_on_select_clear_selection`, disabled by default, to clear transcript selection highlights only after confirmed automatic clipboard delivery.
- Keep local configuration editors usable while disconnected and prevent held activation keys or buffered input from triggering actions across editor and reconnect transitions.

## Testing

Add regression tests and rendering snapshots for panel navigation, search, dependency states, editor handoffs, offline persistence, notification timers, custom filter preservation, and confirmed-copy deselection.

GitOrigin-RevId: a16d218046060fcb6e61705a803fcd9297266e6e

codex-rs/tui/src/keymap_setup/debug.rs

@@ -154,6 +154,10 @@ impl BottomPaneView for KeymapDebugView {
         crate::keymap::KeymapContextSet::raw_key_capture()
     }
 
+    fn accepts_input_when_disconnected(&self) -> bool {
+        true
+    }
+
     fn handle_key_event(&mut self, key_event: KeyEvent) {
         if key_event.kind == KeyEventKind::Release {
             return;