feat(response): Add streamNode() method for Node.js stream support; update tests

ts/core_base/response.ts

@@ -42,4 +42,9 @@ export abstract class CoreResponse<T = any> implements types.ICoreResponse<T> {
    * Get response as a web-style ReadableStream
    */
   abstract stream(): ReadableStream<Uint8Array> | null;
+
+  /**
+   * Get response as a Node.js stream (throws in browser)
+   */
+  abstract streamNode(): NodeJS.ReadableStream | never;
 }

ts/core_base/types.ts

@@ -86,4 +86,5 @@ export interface ICoreResponse<T = any> {
   text(): Promise<string>;
   arrayBuffer(): Promise<ArrayBuffer>;
   stream(): ReadableStream<Uint8Array> | null; // Always returns web-style stream
+  streamNode(): NodeJS.ReadableStream | never; // Returns Node.js stream or throws in browser
 }