init_wizard applies config['oidc'] on first init: creates the
oidc_settings row and, when admin_subject is given, binds the
bootstrap admin so OIDC-only deployments are reachable. Idempotent —
an existing row / admin binding is preserved (later admin edits via
the API survive restarts).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>