Long-running buffered council modes can complete after a supervising shell or agent output session detaches, leaving the successful final JSON inaccessible to the caller.\n\nAdd an opt-in --json-output PATH flag that persists the same complete CouncilResult JSON with owner-only permissions, while preserving existing stdout and exit-code behavior. Reject the unsupported streaming combination before provider calls.\n\nAcceptance criteria:\n- atomic owner-only result file\n- unchanged stdout and exit codes\n- no default persistence\n- offline regression coverage and documentation
Long-running buffered council modes can complete after a supervising shell or agent output session detaches, leaving the successful final JSON inaccessible to the caller.\n\nAdd an opt-in --json-output PATH flag that persists the same complete CouncilResult JSON with owner-only permissions, while preserving existing stdout and exit-code behavior. Reject the unsupported streaming combination before provider calls.\n\nAcceptance criteria:\n- atomic owner-only result file\n- unchanged stdout and exit codes\n- no default persistence\n- offline regression coverage and documentation