BrainCore Foundation 0.82.56 STOPPER_ACTIONS_V1

- Adds active stopper intervention responses to execution actions.
- Adds persistence fields: selected_response, response_notes, response_status, response_selected_at, response_user_id.
- Supports five response families: validate, eliminate, mitigate, renegotiate, accept.
- Shows active intervention block only for blocked actions.
- Adds intervention counter and timeline event STOPPER INTERVENCIÓN.
- Keeps workflows, commitments, automation and global Reality Ledger out of scope.
