Introduce BearerChallengeMiddleware on MCP, Console and Connect GraphQL, Files, and OAuth2 userinfo. Call sites record challenge intent in context via NoteUnauthenticated, NoteInvalidToken, and NoteInsufficientScope; the middleware applies resource_metadata, invalid_token, and insufficient_scope on WriteHeader.
OAuth2 access token middleware flags rejected Bearer tokens for invalid_token challenges. Add Authorizer.ScopesForAction for the scope auth-param.
Signed-off-by: Ludovic Vielle <ludovic@probo.com>
Replace pkg/iam/scopeset with pkg/iam/oauth2scope.Registry, a shared
OAuth2 scope→action registry used by the authorizer, OAuth2 service,
and Connect API. Registration stays open until probod calls Freeze();
read paths (RegisteredScopes, Allows, ValidateScopes) panic before
that.
Drop the leaky APIScopes surface and AllowedAPIScopes on manual
access-token creation in favor of registry.ValidateScopes. Metadata,
protected-resource metadata, and CIMD scope lists are built from
RegisteredScopes() via helpers in pkg/iam/oauth2/scopes.go. Expose
oauth2ScopesSupported as an OAuth2Scope GraphQL scalar.
Signed-off-by: Ludovic Vielle <ludovic@probo.com>
