fix(tui): remove stale readline close listeners to prevent memory leak warning

Clean up the once('close') listener on the readline Interface when
rl.question() resolves normally. Previously, each prompt loop iteration
accumulated a close listener that was never removed, triggering
MaxListenersExceededWarning after 11 prompts.

src/frontends/tui/minimal.ts

@@ -151,8 +151,12 @@ export class MinimalTui {
         resolve('');
         return;
       }
-      this.rl.question(promptText, resolve);
+      const onClose = () => resolve('');
-      this.rl.once('close', () => resolve(''));
+      this.rl.once('close', onClose);
+      this.rl.question(promptText, (answer) => {
+        this.rl?.removeListener('close', onClose);
+        resolve(answer);
+      });
     });
   }