docs: add advanced skills for Vitest, Pinia, and Vue built-ins

Add comprehensive reference documentation for:
- Vitest: environments, projects/workspaces, type testing, vi utilities
- Pinia: HMR, Nuxt integration, SSR setup
- Vue: built-in components (Transition, Teleport, Suspense, KeepAlive) and advanced directives

.agents/skills/vueuse-functions/references/useDrauu.md

@@ -0,0 +1,65 @@
+---
+category: '@Integrations'
+---
+
+# useDrauu
+
+Reactive instance for [drauu](https://github.com/antfu/drauu).
+
+## Install
+
+```bash
+npm i drauu@^0
+```
+
+## Usage
+
+```vue
+<script setup lang="ts">
+import { toRefs } from '@vueuse/core'
+import { useDrauu } from '@vueuse/integrations/useDrauu'
+import { useTemplateRef } from 'vue'
+
+const target = useTemplateRef('target')
+const { undo, redo, canUndo, canRedo, brush } = useDrauu(target)
+const { color, size } = toRefs(brush)
+</script>
+
+<template>
+  <svg ref="target" />
+</template>
+```
+
+## Type Declarations
+
+```ts
+export type UseDrauuOptions = Omit<Options, "el">
+export interface UseDrauuReturn {
+  drauuInstance: Ref<Drauu | undefined>
+  load: (svg: string) => void
+  dump: () => string | undefined
+  clear: () => void
+  cancel: () => void
+  undo: () => boolean | undefined
+  redo: () => boolean | undefined
+  canUndo: ShallowRef<boolean>
+  canRedo: ShallowRef<boolean>
+  brush: Ref<Brush>
+  onChanged: EventHookOn
+  onCommitted: EventHookOn
+  onStart: EventHookOn
+  onEnd: EventHookOn
+  onCanceled: EventHookOn
+}
+/**
+ * Reactive drauu
+ *
+ * @see https://vueuse.org/useDrauu
+ * @param target The target svg element
+ * @param options Drauu Options
+ */
+export declare function useDrauu(
+  target: MaybeComputedElementRef,
+  options?: UseDrauuOptions,
+): UseDrauuReturn
+```