refactor(access): migrate to SDKConfig for authentication and provider management

- Replaced `config.Config` with `SDKConfig` in authentication and provider logic for consistency with SDK changes.
- Updated provider registration, reconciliation, and build functions to align with the `SDKConfig` structure.
- Refactored related imports and handlers to support the new configuration approach.
- Improved clarity and reduced redundancy in API key synchronization and provider initialization.

sdk/cliproxy/builder.go

@@ -184,7 +184,7 @@ func (b *Builder) Build() (*Service, error) {
 	if accessManager == nil {
 		accessManager = sdkaccess.NewManager()
 	}
-	providers, err := sdkaccess.BuildProviders(b.cfg)
+	providers, err := sdkaccess.BuildProviders(&b.cfg.SDKConfig)
 	if err != nil {
 		return nil, err
 	}