feat: add exit slash command alias for quit (#6002)

## Summary
- add the `/exit` slash command alongside `/quit` and reuse shared exit
handling
- refactor the chat widget to funnel quit, exit, logout, and shutdown
flows through a common `request_exit` helper
- add focused unit tests that confirm both `/quit` and `/exit` send an
`ExitRequest`

## Testing
- `just fmt`
- `just fix -p codex-tui`
- `cargo test -p codex-tui`


------
https://chatgpt.com/codex/tasks/task_i_6903d5a8f47c8321bf180f031f2fa330

codex-rs/tui/src/chatwidget.rs

@@ -657,7 +657,7 @@ impl ChatWidget {
     }
 
     fn on_shutdown_complete(&mut self) {
-        self.app_event_tx.send(AppEvent::ExitRequest);
+        self.request_exit();
     }
 
     fn on_turn_diff(&mut self, unified_diff: String) {
@@ -1229,8 +1229,8 @@ impl ChatWidget {
             SlashCommand::Approvals => {
                 self.open_approvals_popup();
             }
-            SlashCommand::Quit => {
-                self.app_event_tx.send(AppEvent::ExitRequest);
+            SlashCommand::Quit | SlashCommand::Exit => {
+                self.request_exit();
             }
             SlashCommand::Logout => {
                 if let Err(e) = codex_core::auth::logout(
@@ -1239,7 +1239,7 @@ impl ChatWidget {
                 ) {
                     tracing::error!("failed to logout: {e}");
                 }
-                self.app_event_tx.send(AppEvent::ExitRequest);
+                self.request_exit();
             }
             SlashCommand::Undo => {
                 self.app_event_tx.send(AppEvent::CodexOp(Op::Undo));
@@ -1593,6 +1593,10 @@ impl ChatWidget {
         }
     }
 
+    fn request_exit(&self) {
+        self.app_event_tx.send(AppEvent::ExitRequest);
+    }
+
     fn request_redraw(&mut self) {
         self.frame_requester.schedule_frame();
     }

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

@@ -851,6 +851,24 @@ fn slash_init_skips_when_project_doc_exists() {
     );
 }
 
+#[test]
+fn slash_quit_requests_exit() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
+
+    chat.dispatch_command(SlashCommand::Quit);
+
+    assert_matches!(rx.try_recv(), Ok(AppEvent::ExitRequest));
+}
+
+#[test]
+fn slash_exit_requests_exit() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();
+
+    chat.dispatch_command(SlashCommand::Exit);
+
+    assert_matches!(rx.try_recv(), Ok(AppEvent::ExitRequest));
+}
+
 #[test]
 fn slash_undo_sends_op() {
     let (mut chat, mut rx, _op_rx) = make_chatwidget_manual();

codex-rs/tui/src/slash_command.rs

@@ -25,6 +25,7 @@ pub enum SlashCommand {
     Mcp,
     Logout,
     Quit,
+    Exit,
     Feedback,
     Rollout,
     TestApproval,
@@ -40,7 +41,7 @@ impl SlashCommand {
             SlashCommand::Compact => "summarize conversation to prevent hitting the context limit",
             SlashCommand::Review => "review my current changes and find issues",
             SlashCommand::Undo => "ask Codex to undo a turn",
-            SlashCommand::Quit => "exit Codex",
+            SlashCommand::Quit | SlashCommand::Exit => "exit Codex",
             SlashCommand::Diff => "show git diff (including untracked files)",
             SlashCommand::Mention => "mention a file",
             SlashCommand::Status => "show current session configuration and token usage",
@@ -75,7 +76,8 @@ impl SlashCommand {
             | SlashCommand::Status
             | SlashCommand::Mcp
             | SlashCommand::Feedback
-            | SlashCommand::Quit => true,
+            | SlashCommand::Quit
+            | SlashCommand::Exit => true,
             SlashCommand::Rollout => true,
             SlashCommand::TestApproval => true,
         }