[jacquard-oauth] add permission set resolution and scope-check feature
- Add expand_permission_set() for LexPermissionSet → Vec<Scope<SmolStr>> conversion
- Add resolve_permission_set() using LexiconSchemaResolver with namespace validation
- Add scope-check feature flag gating jacquard-lexicon dependency
- Add resolved_scopes field to ClientSessionData (feature-gated)
- Add eager resolution infrastructure at session creation