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/useMouseInElement.md

@@ -0,0 +1,132 @@
+---
+category: Elements
+---
+
+# useMouseInElement
+
+Reactive mouse position related to an element
+
+## Usage
+
+```vue
+<script setup lang="ts">
+import { useMouseInElement } from '@vueuse/core'
+import { useTemplateRef } from 'vue'
+
+const target = useTemplateRef('target')
+
+const { x, y, isOutside } = useMouseInElement(target)
+</script>
+
+<template>
+  <div ref="target">
+    <h1>Hello world</h1>
+  </div>
+</template>
+```
+
+## Component Usage
+
+```vue
+<template>
+  <UseMouseInElement v-slot="{ elementX, elementY, isOutside }">
+    x: {{ elementX }}
+    y: {{ elementY }}
+    Is Outside: {{ isOutside }}
+  </UseMouseInElement>
+</template>
+```
+
+## Directive Usage
+
+```vue
+<script setup lang="ts">
+import { vMouseInElement } from '@vueuse/components'
+import { UseMouseSourceType } from '@vueuse/core'
+
+interface MouseInElementType {
+  x: number
+  y: number
+  sourceType: UseMouseSourceType
+  elementX: number
+  elementY: number
+  elementPositionX: number
+  elementPositionY: number
+  elementHeight: number
+  elementWidth: number
+  isOutside: boolean
+}
+
+const options = {
+  handleOutside: true
+}
+function onMouseInElement({ x, y, sourceType, elementX, elementY, elementPositionX, elementPositionY, elementHeight, elementWidth, isOutside }: MouseInElementType) {
+  console.log(x, y, sourceType, elementX, elementY, elementPositionX, elementPositionY, elementHeight, elementWidth, isOutside)
+}
+</script>
+
+<template>
+  <textarea v-mouse-in-element="onMouseInElement" />
+  <!-- with options -->
+  <textarea v-mouse-in-element="[onMouseInElement, options]" />
+</template>
+```
+
+## Type Declarations
+
+```ts
+export interface MouseInElementOptions extends UseMouseOptions {
+  /**
+   * Whether to handle mouse events when the cursor is outside the target element.
+   * When enabled, mouse position will continue to be tracked even when outside the element bounds.
+   *
+   * @default true
+   */
+  handleOutside?: boolean
+  /**
+   * Listen to window resize event
+   *
+   * @default true
+   */
+  windowScroll?: boolean
+  /**
+   * Listen to window scroll event
+   *
+   * @default true
+   */
+  windowResize?: boolean
+}
+export interface UseMouseInElementReturn extends UseMouseReturn {
+  elementX: ShallowRef<number>
+  elementY: ShallowRef<number>
+  elementPositionX: ShallowRef<number>
+  elementPositionY: ShallowRef<number>
+  elementHeight: ShallowRef<number>
+  elementWidth: ShallowRef<number>
+  isOutside: ShallowRef<boolean>
+  stop: () => void
+}
+/**
+ * Reactive mouse position related to an element.
+ *
+ * @see https://vueuse.org/useMouseInElement
+ * @param target
+ * @param options
+ */
+export declare function useMouseInElement(
+  target?: MaybeElementRef,
+  options?: MouseInElementOptions,
+): {
+  x: ShallowRef<number>
+  y: ShallowRef<number>
+  sourceType: ShallowRef<UseMouseSourceType>
+  elementX: ShallowRef<number, number>
+  elementY: ShallowRef<number, number>
+  elementPositionX: ShallowRef<number, number>
+  elementPositionY: ShallowRef<number, number>
+  elementHeight: ShallowRef<number, number>
+  elementWidth: ShallowRef<number, number>
+  isOutside: ShallowRef<boolean, boolean>
+  stop: () => void
+}
+```