Add /title terminal title override

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

codex-rs/tui/src/bottom_pane/slash_commands.rs

@@ -82,6 +82,14 @@ mod tests {
         );
     }
 
+    #[test]
+    fn title_command_resolves_for_dispatch() {
+        assert_eq!(
+            find_builtin_command("title", all_enabled_flags()),
+            Some(SlashCommand::Title)
+        );
+    }
+
     #[test]
     fn fast_command_is_hidden_when_disabled() {
         let mut flags = all_enabled_flags();