Add ARTIFACTAPI_AUTH_UPLOADS to require a verified token for local
uploads, deletes, evictions, /api/v1 publishes and /v2 push. Accept the
token as Bearer, Token, Basic password or bare header, and serve a
Docker registry token endpoint so pulls stay anonymous.
Remote and virtual configuration writes are unauthenticated, so anything that can reach the API can repoint or delete repos. Vault identity OIDC tokens give callers a verifiable identity.
- add `ARTIFACTAPI_OIDC_ISSUER`/`ARTIFACTAPI_OIDC_AUDIENCE`; unset issuer keeps auth off
- require a JWKS-verified bearer token on POST/PUT/DELETE of `/api/v2/remotes` and `/api/v2/virtuals`, 401 otherwise
- leave uploads, object deletes, probe, reads and `/v2` open
- discover the issuer lazily with a 10s client timeout; fail fast with 503 for 15s after a failed discovery
- log the verified `sub`; allow `Authorization` in CORS
Reviewed-on: #136
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>