When a profile is deleted, only the current session was being
invalidated. Other active sessions on different devices remained
functional until the background cleanup task completed.
Add session/invalidate-all helper that deletes all sessions for
a profile by profile_id, and call it from delete-profile before
the response transform. This ensures immediate access revocation
across all devices when an account is deleted.
Closes#11114
AI-assisted-by: qwen3.7-plus