Phase 1, Task 1.4. Records every auth event (login start/success/failure,
logout, refresh success/failure, revoke, session verify failure, WS
ticket mint) as one JSON object per line. Token-like kwargs (access_token,
refresh_token, code, code_verifier, state, ticket, cookie, Authorization)
are dropped before serialisation so the log never contains live secrets.
Write failures log at WARNING but never raise — auth flows must not fail
because the audit logger broke.
