feat(deploy): notify clients of new releases

tests/deployment-contract.test.ts

@@ -110,6 +110,20 @@ describe("production deployment contract", () => {
     );
     expect(workflow).not.toMatch(/playwright|chromium/iu);
   });
+
+  it("mounts the deployment stream and offers a full reload for new releases", async () => {
+    const [layout, notifier, route] = await Promise.all([
+      repositoryFile("app/layout.tsx"),
+      repositoryFile("components/deployment-update-notifier.tsx"),
+      repositoryFile("app/api/active/route.ts"),
+    ]);
+
+    expect(layout).toContain("<DeploymentUpdateNotifier");
+    expect(notifier).toContain('new EventSource("/api/active")');
+    expect(notifier).toContain("window.location.reload()");
+    expect(notifier).toContain('label: "รีโหลด"');
+    expect(route).toContain('channel.sendNamed("deployment", deploymentId)');
+  });
 });
 
 describe("environment template contract", () => {