fix(core,testing): improve type safety and update tests for latest tstest and storage APIs

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartregistry',
-  version: '2.9.1',
+  version: '2.9.2',
   description: 'A composable TypeScript library implementing OCI, NPM, Maven, Cargo, Composer, PyPI, and RubyGems registries for building unified container and package registries'
 }

ts/core/classes.baseregistry.ts

@@ -6,7 +6,12 @@ import type { IRequestContext, IResponse, IAuthToken, IRequestActor } from './in
  */
 export abstract class BaseRegistry {
   protected getHeader(contextOrHeaders: IRequestContext | Record<string, string>, name: string): string | undefined {
-    const headers = 'headers' in contextOrHeaders ? contextOrHeaders.headers : contextOrHeaders;
+    const headers: Record<string, string> =
+      'headers' in contextOrHeaders &&
+      typeof contextOrHeaders.headers === 'object' &&
+      contextOrHeaders.headers !== null
+        ? contextOrHeaders.headers
+        : contextOrHeaders as Record<string, string>;
     if (headers[name] !== undefined) {
       return headers[name];
     }