feat(events): stream Redis invalidations over SSE

app/api/events/admin/route.ts

@@ -0,0 +1,24 @@
+import {
+  AdminAuthorizationError,
+  requireAdmin,
+} from "@/lib/auth/server";
+import {
+  createRedisEventResponse,
+  eventsUnavailableResponse,
+} from "@/lib/events/redis-stream";
+
+export async function GET(request: Request) {
+  try {
+    await requireAdmin();
+  } catch (cause) {
+    if (cause instanceof AdminAuthorizationError) {
+      return Response.json({ error: "unauthorized" }, { status: 401 });
+    }
+    throw cause;
+  }
+  try {
+    return await createRedisEventResponse("admin", request.signal);
+  } catch {
+    return eventsUnavailableResponse();
+  }
+}