Schema for flag change audit records.
Each row represents a single value change to a flag, recording who changed it, what the old and new values were, and when it happened.
Audit logging is opt-in — enable it with audit: true in your config module:
use PhoenixFlags,
otp_app: :my_app,
repo: MyApp.Repo,
audit: true,
actor_fn: &MyApp.Flags.current_user/1