Server does not support resource template parameter substitution

- **Target:** server
- **Component:** sdk-server
- **Scenarios:** `resources-templates-read`

### Root cause

The SDK's `Server` / `FeatureRegistry` does not implement `addResourceTemplate()` with URI pattern matching. Resources are looked up by exact URI, so a request for `test://template/123/data` does not match the registered template `test://template/{id}/data`.

Related: #502 