fix: align headless interactive tool behavior with bidirectional parity (#894)

src/tools/impl/ExitPlanMode.ts

@@ -3,7 +3,17 @@
  * Exits plan mode - the plan is read from the plan file by the UI
  */
 
+import { permissionMode } from "../../permissions/mode";
+
 export async function exit_plan_mode(): Promise<{ message: string }> {
+  // In interactive mode, the UI restores mode before calling this tool.
+  // In headless/bidirectional mode, there is no UI layer to do that, so
+  // restore here as a fallback to avoid getting stuck in plan mode.
+  if (permissionMode.getMode() === "plan") {
+    const restoredMode = permissionMode.getModeBeforePlan() ?? "default";
+    permissionMode.setMode(restoredMode);
+  }
+
   // Return confirmation message that plan was approved
   // Note: The plan is read from the plan file by the UI before this return is shown
   // The UI layer checks if the plan file exists and auto-rejects if not