Improve conversation realtime refresh and heartbeat defaults

tests/local-agent-heartbeat-defaults.test.mjs

@@ -0,0 +1,29 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFile } from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
+
+test("shipped local-agent configs use the faster heartbeat default", async () => {
+  const exampleConfig = JSON.parse(
+    await readFile(path.join(repoRoot, "local-agent", "config.example.json"), "utf8"),
+  );
+  const cloudConfig = JSON.parse(
+    await readFile(path.join(repoRoot, "local-agent", "config.cloud.json"), "utf8"),
+  );
+
+  assert.equal(exampleConfig.heartbeatIntervalMs, 15_000);
+  assert.equal(cloudConfig.heartbeatIntervalMs, 15_000);
+});
+
+test("device enrollment snippet advertises the faster heartbeat default", async () => {
+  const source = await readFile(path.join(repoRoot, "src", "components", "app-ui.tsx"), "utf8");
+  assert.match(source, /heartbeatIntervalMs:\s*15000/);
+});
+
+test("local-agent runtime falls back to the faster heartbeat default", async () => {
+  const source = await readFile(path.join(repoRoot, "local-agent", "server.mjs"), "utf8");
+  assert.match(source, /heartbeatIntervalMs\s*\?\?\s*15000/);
+});