feat: reset memories button (#17937)

<img width="720" height="175" alt="Screenshot 2026-04-15 at 14 35 02"
src="https://github.com/user-attachments/assets/041d73ff-8c16-42a9-8e92-c245805084f0"
/>

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

@@ -0,0 +1,12 @@
+---
+source: tui/src/chatwidget/tests/popups_and_settings.rs
+expression: popup
+---
+  Reset all memories?
+
+› Reset all memories  Delete local memory files and rollout summaries.
+  Go back             Return to memory settings.
+
+
+
+  Press enter to confirm or esc to go back

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

@@ -9,7 +9,9 @@ expression: popup
                          next thread.
   [ ] Generate memories  Generate memories from the following threads. Current
                          thread included.
+  Reset all memories     Clear local memory files and summaries. Existing
+                         threads stay intact.
 
   Learn more: https://developers.openai.com/codex/memories
 
-  Press space to toggle; enter to save
+  Press space to toggle; enter to save or select

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

@@ -1543,6 +1543,22 @@ async fn memories_settings_popup_snapshot() {
     assert_chatwidget_snapshot!("memories_settings_popup", popup);
 }
 
+#[tokio::test]
+async fn memories_reset_confirmation_snapshot() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(/*model_override*/ None).await;
+    chat.set_feature_enabled(Feature::MemoryTool, /*enabled*/ true);
+    chat.config.memories.use_memories = true;
+    chat.config.memories.generate_memories = false;
+
+    chat.open_memories_popup();
+    chat.handle_key_event(KeyEvent::from(KeyCode::Down));
+    chat.handle_key_event(KeyEvent::from(KeyCode::Down));
+    chat.handle_key_event(KeyEvent::from(KeyCode::Enter));
+
+    let popup = render_bottom_popup(&chat, /*width*/ 80);
+    assert_chatwidget_snapshot!("memories_reset_confirmation", popup);
+}
+
 #[tokio::test]
 async fn memories_settings_toggle_saves_on_enter() {
     let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(/*model_override*/ None).await;
@@ -1564,6 +1580,22 @@ async fn memories_settings_toggle_saves_on_enter() {
     );
 }
 
+#[tokio::test]
+async fn memories_reset_confirmation_sends_event_on_confirm() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(/*model_override*/ None).await;
+    chat.set_feature_enabled(Feature::MemoryTool, /*enabled*/ true);
+    chat.config.memories.use_memories = true;
+    chat.config.memories.generate_memories = false;
+
+    chat.open_memories_popup();
+    chat.handle_key_event(KeyEvent::from(KeyCode::Down));
+    chat.handle_key_event(KeyEvent::from(KeyCode::Down));
+    chat.handle_key_event(KeyEvent::from(KeyCode::Enter));
+    chat.handle_key_event(KeyEvent::from(KeyCode::Enter));
+
+    assert_matches!(rx.try_recv(), Ok(AppEvent::ResetMemories));
+}
+
 #[tokio::test]
 async fn model_selection_popup_snapshot() {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual(Some("gpt-5-codex")).await;