Skip disabled rows in selection menu numbering and default focus (#19170)

Selection menus in the TUI currently let disabled rows interfere with
numbering and default focus. This makes mixed menus harder to read and
can land selection on rows that are not actionable. This change updates
the shared selection-menu behavior in list_selection_view so disabled
rows are not selected when these views open, and prevents them from
being numbered like selectable rows.

- Disabled rows no longer receive numeric labels
- Digit shortcuts map to enabled rows only
- Default selection moves to the first enabled row in mixed menus
- Updated affected snapshot
- Added snapshot coverage for a plugin detail error popup
- Added a focused unit test for shared selection-view behavior

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__plugin_detail_error_popup.snap

@@ -0,0 +1,11 @@
+---
+source: tui/src/chatwidget/tests.rs
+expression: popup
+---
+  Plugins
+  Failed to load plugin details.
+
+     Plugin detail unavailable  Failed to load plugin details.
+› 1. Back to plugins            Return to the plugin list.
+
+  Press esc to close.

codex-rs/tui/src/chatwidget/snapshots/codex_tui__chatwidget__tests__realtime_microphone_picker_popup.snap

@@ -5,14 +5,14 @@ expression: popup
   Select Microphone
   Saved devices apply to realtime voice only.
 
-  1. System default                                Use your operating system
+› 1. System default                                Use your operating system
                                                    default device.
-›    Unavailable: Studio Mic (current) (disabled)  Configured device is not
+     Unavailable: Studio Mic (current) (disabled)  Configured device is not
                                                    currently available.
                                                    (disabled: Reconnect the
                                                    device or choose another
                                                    one.)
-  3. Built-in Mic
-  4. USB Mic
+  2. Built-in Mic
+  3. USB Mic
 
   Press enter to confirm or esc to go back

codex-rs/tui/src/chatwidget/tests/popups_and_settings.rs

@@ -247,6 +247,34 @@ async fn plugin_detail_popup_hides_disclosure_for_installed_plugins() {
     );
 }
 
+#[tokio::test]
+async fn plugin_detail_error_popup_skips_disabled_row_numbering() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(/*model_override*/ None).await;
+    chat.set_feature_enabled(Feature::Plugins, /*enabled*/ true);
+
+    let response = plugins_test_response(vec![plugins_test_curated_marketplace(vec![
+        plugins_test_summary(
+            "plugin-figma",
+            "figma",
+            Some("Figma"),
+            Some("Design handoff."),
+            /*installed*/ false,
+            /*enabled*/ true,
+            PluginInstallPolicy::Available,
+        ),
+    ])]);
+    let cwd = chat.config.cwd.clone();
+    chat.on_plugins_loaded(cwd.to_path_buf(), Ok(response));
+    chat.add_plugins_output();
+    chat.on_plugin_detail_loaded(
+        cwd.to_path_buf(),
+        Err("Failed to load plugin details.".to_string()),
+    );
+
+    let popup = render_bottom_popup(&chat, /*width*/ 100);
+    assert_chatwidget_snapshot!("plugin_detail_error_popup", popup);
+}
+
 #[tokio::test]
 async fn plugins_popup_refresh_preserves_selected_row_position() {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual(/*model_override*/ None).await;