9da913080f
Every incident-mutation handler read userFromContext(ctx) and wrote the result's .ID into acknowledged_by/incident_events.user_id without checking the ok bool. For a team-scoped service-account caller this returned a zero-value user id, which violated the users(id) FK and 500'd on acknowledge, unacknowledge, resolve, snooze, unsnooze and create-note. handleDeleteNote didn't crash but silently matched zero rows instead (WHERE user_id = 0), so a service account could never delete its own note. Add acknowledged_by_service_account_id (incidents) and service_account_id (incident_events) as nullable FKs to service_accounts(id), parallel to and mutually exclusive with the existing human columns (migration 015, with a CHECK enforcing the exclusion). Route every one of the six handlers plus delete-note through a new callerActorIDs() helper that branches on Caller.AsHuman()/ServiceAccountID() instead of assuming a human, and thread a serviceAccountID parameter through logEvent and the new acknowledgeIncidentAs (acknowledgeIncident itself is untouched: its only other caller, the push-notification Acknowledge button, is always human). Render the new actor distinctly from both a human and "the server acted" in the web UI's incident timeline and facts card. handleIncidentAssign, handleIncidentArchive and handleIncidentUnarchive are deliberately not touched here — they track no actor at all today, for anyone, which is a separate pre-existing gap (follow-up issue to come). Fixes #25