Add realtime audio device picker (#12850)

## Summary
- add a dedicated /audio picker for realtime microphone and speaker
selection
- persist realtime audio choices and prompt to restart only local audio
when voice is live
- add snapshot coverage for the new picker surfaces

## Validation
- cargo test -p codex-tui
- cargo insta accept
- just fix -p codex-tui
- just fmt

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

@@ -7,6 +7,8 @@
 use super::*;
 use crate::app_event::AppEvent;
 use crate::app_event::ExitMode;
+#[cfg(all(not(target_os = "linux"), feature = "voice-input"))]
+use crate::app_event::RealtimeAudioDeviceKind;
 use crate::app_event_sender::AppEventSender;
 use crate::bottom_pane::FeedbackAudience;
 use crate::bottom_pane::LocalImageAttachment;
@@ -6001,6 +6003,62 @@ async fn personality_selection_popup_snapshot() {
     assert_snapshot!("personality_selection_popup", popup);
 }
 
+#[cfg(all(not(target_os = "linux"), feature = "voice-input"))]
+#[tokio::test]
+async fn realtime_audio_selection_popup_snapshot() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.2-codex")).await;
+    chat.open_realtime_audio_popup();
+
+    let popup = render_bottom_popup(&chat, 80);
+    assert_snapshot!("realtime_audio_selection_popup", popup);
+}
+
+#[cfg(all(not(target_os = "linux"), feature = "voice-input"))]
+#[tokio::test]
+async fn realtime_audio_selection_popup_narrow_snapshot() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.2-codex")).await;
+    chat.open_realtime_audio_popup();
+
+    let popup = render_bottom_popup(&chat, 56);
+    assert_snapshot!("realtime_audio_selection_popup_narrow", popup);
+}
+
+#[cfg(all(not(target_os = "linux"), feature = "voice-input"))]
+#[tokio::test]
+async fn realtime_microphone_picker_popup_snapshot() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.2-codex")).await;
+    chat.config.realtime_audio.microphone = Some("Studio Mic".to_string());
+    chat.open_realtime_audio_device_selection_with_names(
+        RealtimeAudioDeviceKind::Microphone,
+        vec!["Built-in Mic".to_string(), "USB Mic".to_string()],
+    );
+
+    let popup = render_bottom_popup(&chat, 80);
+    assert_snapshot!("realtime_microphone_picker_popup", popup);
+}
+
+#[cfg(all(not(target_os = "linux"), feature = "voice-input"))]
+#[tokio::test]
+async fn realtime_audio_picker_emits_persist_event() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(Some("gpt-5.2-codex")).await;
+    chat.open_realtime_audio_device_selection_with_names(
+        RealtimeAudioDeviceKind::Speaker,
+        vec!["Desk Speakers".to_string(), "Headphones".to_string()],
+    );
+
+    chat.handle_key_event(KeyEvent::new(KeyCode::Down, KeyModifiers::NONE));
+    chat.handle_key_event(KeyEvent::new(KeyCode::Down, KeyModifiers::NONE));
+    chat.handle_key_event(KeyEvent::new(KeyCode::Enter, KeyModifiers::NONE));
+
+    assert_matches!(
+        rx.try_recv(),
+        Ok(AppEvent::PersistRealtimeAudioDeviceSelection {
+            kind: RealtimeAudioDeviceKind::Speaker,
+            name: Some(name),
+        }) if name == "Headphones"
+    );
+}
+
 #[tokio::test]
 async fn model_picker_hides_show_in_picker_false_models_from_cache() {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("test-visible-model")).await;