Feature 19: Admin PWA (#187-#210) (#211)

Co-authored-by: dev_agent <17+dev_agent@code.cubecraftcreations.com>
Co-committed-by: dev_agent <17+dev_agent@code.cubecraftcreations.com>

admin/src/api/testStream.ts

@@ -0,0 +1,39 @@
+/**
+ * Test helper: a controllable text/event-stream Response whose body the test
+ * feeds chunk by chunk (so a frame can be split across chunk boundaries).
+ */
+export interface TestStream {
+  response: Response;
+  push(text: string): void;
+  close(): void;
+  /** True once the reader cancelled the body (the stream was torn down). */
+  cancelled(): boolean;
+}
+
+export function testStream(): TestStream {
+  const encoder = new TextEncoder();
+  let controller!: ReadableStreamDefaultController<Uint8Array>;
+  let cancelled = false;
+  const body = new ReadableStream<Uint8Array>({
+    start(c) {
+      controller = c;
+    },
+    cancel() {
+      cancelled = true;
+    },
+  });
+  return {
+    response: new Response(body, {
+      status: 200,
+      headers: { "Content-Type": "text/event-stream" },
+    }),
+    push: (text) => controller.enqueue(encoder.encode(text)),
+    close: () => controller.close(),
+    cancelled: () => cancelled,
+  };
+}
+
+/** One SSE frame exactly as api/sse.py writes it. */
+export function frame(type: string, payload: unknown): string {
+  return `event: ${type}\ndata: ${JSON.stringify(payload)}\n\n`;
+}