Log agent permission toggle changes

Record who changed an agent-facing permission setting and when.

Transcript Context

While discussing future agent-level toggles, the team said support would need a timestamped audit trail whenever an agent changes a setting. Shayna specifically called out the need to show that an agent made the change so teams are not blamed for it later by the agent. The conversation suggested some form of activity table or system log that records the actor, time, and change made.