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/watchThrottled.md

@@ -0,0 +1,108 @@
+---
+category: Watch
+alias: throttledWatch
+---
+
+# watchThrottled
+
+Throttled watch. The callback will be invoked at most once per specified duration.
+
+## Usage
+
+Similar to `watch`, but offering extra options `throttle`, `trailing`, and `leading` which will be applied to the callback function.
+
+```ts
+import { watchThrottled } from '@vueuse/core'
+
+watchThrottled(
+  source,
+  () => { console.log('changed!') },
+  { throttle: 500 },
+)
+```
+
+### Options
+
+| Option     | Type                       | Default | Description                               |
+| ---------- | -------------------------- | ------- | ----------------------------------------- |
+| `throttle` | `MaybeRefOrGetter<number>` | `0`     | Throttle interval in ms (can be reactive) |
+| `trailing` | `boolean`                  | `true`  | Invoke on the trailing edge               |
+| `leading`  | `boolean`                  | `true`  | Invoke on the leading edge                |
+
+All standard `watch` options (`deep`, `immediate`, `flush`, etc.) are also supported.
+
+### Leading and Trailing
+
+Control when the callback is invoked:
+
+```ts
+import { watchThrottled } from '@vueuse/core'
+
+// Only invoke at the start of each throttle period
+watchThrottled(source, callback, {
+  throttle: 500,
+  leading: true,
+  trailing: false,
+})
+
+// Only invoke at the end of each throttle period
+watchThrottled(source, callback, {
+  throttle: 500,
+  leading: false,
+  trailing: true,
+})
+```
+
+## How It Works
+
+It's essentially a shorthand for the following code:
+
+```ts
+import { throttleFilter, watchWithFilter } from '@vueuse/core'
+
+watchWithFilter(
+  source,
+  () => { console.log('changed!') },
+  {
+    eventFilter: throttleFilter(500),
+  },
+)
+```
+
+## Type Declarations
+
+```ts
+export interface WatchThrottledOptions<
+  Immediate,
+> extends WatchOptions<Immediate> {
+  throttle?: MaybeRefOrGetter<number>
+  trailing?: boolean
+  leading?: boolean
+}
+export declare function watchThrottled<
+  T extends Readonly<MultiWatchSources>,
+  Immediate extends Readonly<boolean> = false,
+>(
+  sources: [...T],
+  cb: WatchCallback<MapSources<T>, MapOldSources<T, Immediate>>,
+  options?: WatchThrottledOptions<Immediate>,
+): WatchHandle
+export declare function watchThrottled<
+  T,
+  Immediate extends Readonly<boolean> = false,
+>(
+  source: WatchSource<T>,
+  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
+  options?: WatchThrottledOptions<Immediate>,
+): WatchHandle
+export declare function watchThrottled<
+  T extends object,
+  Immediate extends Readonly<boolean> = false,
+>(
+  source: T,
+  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
+  options?: WatchThrottledOptions<Immediate>,
+): WatchHandle
+/** @deprecated use `watchThrottled` instead */
+export declare const throttledWatch: typeof watchThrottled
+```