feat: add time-based render throttle (~30fps) matching Ink

Add leading+trailing throttle to the commit scheduler in production mode.
In debug/test mode (immediate: true), commits fire without delay to
preserve test determinism. Adjusted the non-debug static test to account
for the throttle timer.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/runtime-tests/integration/components/static.test.tsx

@@ -111,6 +111,8 @@ test("Static flush clears the dynamic frame first (non-debug mode)", async () =>
   stdout.chunks.length = 0;
   items.value = ["STATIC_ITEM"];
   await nextTick();
+  // Wait for the render throttle trailing timer (~32ms) to fire in production mode.
+  await new Promise((r) => setTimeout(r, 50));
 
   // Collect everything written during this render cycle
   const renderOutput = stdout.chunks.join("");

packages/runtime-tests/integration/scheduler-throttle.test.tsx

@@ -0,0 +1,24 @@
+import { defineComponent, nextTick, shallowRef } from "vue";
+import { expect, test } from "vite-plus/test";
+import { render } from "@vue-tui/testing";
+import { Text } from "@vue-tui/runtime";
+
+test("rapid mutations in debug mode produce immediate frames (no throttle)", async () => {
+  const count = shallowRef(0);
+  const App = defineComponent(() => {
+    return () => <Text>{String(count.value)}</Text>;
+  });
+
+  const { frames } = await render(App);
+  const before = frames.length;
+
+  // Each mutation + tick should produce a frame in debug mode
+  for (let i = 1; i <= 5; i++) {
+    count.value = i;
+    await nextTick();
+    await nextTick();
+  }
+
+  // In debug mode (used by testing), each mutation produces a frame
+  expect(frames.length - before).toBe(5);
+});