v2.10.5: feat(auth): Reintroduce optional operational authentication log

Reintroduces the `auth_log` table and `setAuthLog(true)` functionality, previously removed, to provide an operational overview of authentication events.

This log is strictly for internal diagnostics and support ("who signed in, when, and from where"), offering an in-application view. It is explicitly distinguished from a formal audit trail, which requires external, tamper-proof storage.

This design allows projects to use both an internal operational log and an external audit trail (via `$onAuthEvent`) with differing retention policies and audiences. Events are recorded directly via DBAL, bypassing ORM for reliable, atomic writes.