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/useMouse.md

@@ -0,0 +1,113 @@
+---
+category: Sensors
+---
+
+# useMouse
+
+Reactive mouse position
+
+## Basic Usage
+
+```ts twoslash
+import { useMouse } from '@vueuse/core'
+
+const { x, y, sourceType } = useMouse()
+```
+
+Touch is enabled by default. To only detect mouse changes, set `touch` to `false`.
+The `dragover` event is used to track mouse position while dragging.
+
+```ts twoslash
+import { useMouse } from '@vueuse/core'
+// ---cut---
+const { x, y } = useMouse({ touch: false })
+```
+
+## Custom Extractor
+
+It's also possible to provide a custom extractor function to get the position from the event.
+
+```ts twoslash
+import type { UseMouseEventExtractor } from '@vueuse/core'
+import { useMouse, useParentElement } from '@vueuse/core'
+
+const parentEl = useParentElement()
+
+const extractor: UseMouseEventExtractor = event => (
+  event instanceof MouseEvent
+    ? [event.offsetX, event.offsetY]
+    : null
+)
+
+const { x, y, sourceType } = useMouse({ target: parentEl, type: extractor })
+```
+
+## Component Usage
+
+```vue
+<template>
+  <UseMouse v-slot="{ x, y }">
+    x: {{ x }}
+    y: {{ y }}
+  </UseMouse>
+</template>
+```
+
+## Type Declarations
+
+```ts
+export type UseMouseCoordType = "page" | "client" | "screen" | "movement"
+export type UseMouseSourceType = "mouse" | "touch" | null
+export type UseMouseEventExtractor = (
+  event: MouseEvent | Touch,
+) => [x: number, y: number] | null | undefined
+export interface UseMouseOptions
+  extends ConfigurableWindow, ConfigurableEventFilter {
+  /**
+   * Mouse position based by page, client, screen, or relative to previous position
+   *
+   * @default 'page'
+   */
+  type?: UseMouseCoordType | UseMouseEventExtractor
+  /**
+   * Listen events on `target` element
+   *
+   * @default 'Window'
+   */
+  target?: MaybeRefOrGetter<Window | EventTarget | null | undefined>
+  /**
+   * Listen to `touchmove` events
+   *
+   * @default true
+   */
+  touch?: boolean
+  /**
+   * Listen to `scroll` events on window, only effective on type `page`
+   *
+   * @default true
+   */
+  scroll?: boolean
+  /**
+   * Reset to initial value when `touchend` event fired
+   *
+   * @default false
+   */
+  resetOnTouchEnds?: boolean
+  /**
+   * Initial values
+   */
+  initialValue?: Position
+}
+export interface UseMouseReturn {
+  x: ShallowRef<number>
+  y: ShallowRef<number>
+  sourceType: ShallowRef<UseMouseSourceType>
+}
+/**
+ * Reactive mouse position.
+ *
+ * @see https://vueuse.org/useMouse
+ * @param options
+ */
+export declare function useMouse(options?: UseMouseOptions): UseMouseReturn
+```