Replace the handwritten Authentik JWT checks with github.com/zitadel/zitadel-go/v3.
What the SDK now owns:
- OIDC discovery (client.Discover) to find issuer and JWKS URI
- remote, auto-refreshing JWKS (rp.NewRemoteKeySet)
- signature, expiry and issuer checks (op.NewAccessTokenVerifier,
op.VerifyAccessToken)
- the verified claim set and role lookup (oauth.IntrospectionContext,
IsGrantedRole)
What stays local:
- a multi-audience allow-list, because this gateway is a shared resource
server and the SDK's oauth.WithJWT accepts exactly one client ID
- an adapter from IntrospectionContext to jwt.MapClaims so the rest of the
gateway keeps one claim representation
Other changes:
- issuer is configuration-driven; the hardcoded authentik.riotpiao.com
check is gone
- aud may be a string or an array (ZITADEL sends an array)
- CheckPermissions also reads urn:zitadel:iam:org:project:roles, the claim
ZITADEL uses for project roles
- requiredCapability accepts a comma-separated list, so llm:inference and
llm-inference both satisfy the LLM gate
- a five-segment token is reported as an encrypted JWE with the fix in the
message, instead of failing as a bad signature
Config: auth.zitadelDomain turns the SDK path on; jwksUrl stays supported for
the legacy path and for tests.
