Add experiments folder. Add usage.md and SKILL.md. Fix Sheet interactions and add dynamic sheet mode.

experiments/router-guard-history/src/main.ts

@@ -0,0 +1,13 @@
+import { createApp } from "vue";
+import App from "./App.vue";
+import { record } from "./experiment";
+import { router } from "./router";
+import "./style.css";
+
+const app = createApp(App);
+app.use(router);
+app.mount("#app");
+
+void router.isReady().then(() => {
+  record("router: ready", router.currentRoute.value.fullPath);
+});