The audit logger is opened at startup (exit 2 on failure) and obtained before
every call, which is refused with audit_unavailable otherwise. Audit records only
take validated path and sudo values and use the request id as correlation id. The
rate limiter evicts idle keys, caps tracked keys, audits the first excess per key
and window and uses the settings passed to the app. FORWARDED_ALLOW_IPS is now a
setting, and startup warns about a missing host allow-list and unavailable OAuth.
Adds the pydantic-settings Settings with validated GITEA_URL, OAuth scopes
and toolsets, the argparse CLI skeleton, catalog.model, identity and
GiteaAPIError. Test fixtures now isolate env, cwd and state paths in tmp.
Latte