Keep TUI preferences editable when execution settings are invalid (#56091)

## Why

Saving a local preference could succeed but fail to apply live because reloading the full configuration also resolved execution settings. An unknown `model_provider`, for example, prevented the preference from taking effect.

## What changed

Reload config-panel preferences from the configuration layer stack into `LocalSettings` without rebuilding execution settings. Preserve CLI overrides, loader overrides, cloud configuration, and the existing choice of working directory.

## Testing

Extend the offline remote-session preference test with an unknown `model_provider` override, verifying that automatic recap and paste detection preferences still persist and apply live.

GitOrigin-RevId: 2377a01c77f3cb978a7ee6cd67c1fe89361131fb

codex-rs/tui/src/app/config_panel.rs

@@ -4,6 +4,8 @@ use super::*;
 use crate::config_panel::ConfigPreference;
 use crate::config_panel::ConfigToggle;
 use crate::config_update::format_config_error;
+use crate::legacy_core::config::load_config_toml_with_layer_stack;
+use crate::local_settings::LocalSettings;
 
 impl App {
     pub(super) async fn save_config_preference(
@@ -34,8 +36,26 @@ impl App {
         } else {
             self.chat_widget.config_ref().cwd.to_path_buf()
         };
-        let resolved = match self.rebuild_config_for_cwd(config_cwd).await {
-            Ok(config) => crate::local_settings::LocalSettings::from(&config),
+        let resolved = match async {
+            let cwd = AbsolutePathBuf::relative_to_current_dir(&config_cwd)?;
+            let bootstrap = load_config_toml_with_layer_stack(
+                self.local_settings.codex_home.as_path(),
+                Some(&cwd),
+                self.cli_kv_overrides.clone(),
+                codex_config::ConfigLoadOptions {
+                    loader_overrides: self.loader_overrides.clone(),
+                    cloud_config_bundle: self.cloud_config_bundle.clone(),
+                    ..Default::default()
+                },
+            )
+            .await?;
+            LocalSettings::from_bootstrap(&bootstrap, self.local_settings.codex_home.clone())
+                .map_err(std::io::Error::other)
+        }
+        .await
+        .wrap_err_with(|| format!("Failed to rebuild config for cwd {}", config_cwd.display()))
+        {
+            Ok(settings) => settings,
             Err(error) => {
                 self.chat_widget
                     .refresh_config_panel(

codex-rs/tui/src/app/config_panel_tests.rs

@@ -92,6 +92,8 @@ async fn config_toggle_save_uses_host_config_and_applies_live_while_offline() ->
     app.chat_widget = ChatWidget::new_with_app_event(init);
     app.local_settings.tui.auto_recap = true;
     app.chat_widget.local_settings.tui.auto_recap = true;
+    // Resolving execution settings would fail, but local preferences remain editable.
+    app.cli_kv_overrides = vec![("model_provider".into(), "missing-provider".into())];
 
     Box::pin(app.handle_event(
         &mut tui,