19162b1fe6
When a plan reaches a terminal state (all items done or blocked) in interactive mode, automatically exit plan mode and return to normal prompt. Changes: - Add Agent::is_plan_terminal() method to check if plan is complete - Add check_and_exit_plan_mode_if_terminal() helper in interactive.rs - Call the helper after each execute_user_input() to detect completion Fixes issue where plan mode prompt ' >> ' persisted after plan completion.