fixup! feat(platform): support external token providers and simplify caching

Author: akunft

specifications/SPEC_PLATFORM_SERVICE.md

@@ -111,7 +111,7 @@ platform/
 | Output Type      | Destination         | Format/Type                  | Success Criteria                                    | Code Location                                        |
 | ---------------- | ------------------- | ---------------------------- | --------------------------------------------------- | ---------------------------------------------------- |
 | JWT Access Token | Token cache/memory  | String                       | Valid JWT with required claims and unexpired        | `_authentication.py::get_token()` return value       |
-| API Client       | Client applications | `_AuthenticatedApi` object   | Authenticated and configured for target environment | `_client.py::Client.get_api_client()` factory method |
+| API Client       | Client applications | `Client` object              | Authenticated and configured for target environment | `_client.py::Client.__init__()` constructor          |
 | User Information | CLI/Application     | UserInfo/Me objects    | Complete user and organization data                 | `_service.py::Service.get_user_info()` method        |
 | Health Status    | Monitoring systems  | Health object          | Accurate service and dependency status              | `_service.py::Service.health()` method               |
 | Downloaded Files | Local filesystem    | Binary/structured data | Verified checksums and complete downloads           | `_utils.py` download functions and `ApplicationRun`  |