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/watchDebounced.md

@@ -0,0 +1,101 @@
+---
+category: Watch
+alias: debouncedWatch
+---
+
+# watchDebounced
+
+Debounced watch. The callback will only be invoked after the source stops changing for the specified duration.
+
+## Usage
+
+Similar to `watch`, but offering extra options `debounce` and `maxWait` which will be applied to the callback function.
+
+```ts
+import { watchDebounced } from '@vueuse/core'
+
+watchDebounced(
+  source,
+  () => { console.log('changed!') },
+  { debounce: 500, maxWait: 1000 },
+)
+```
+
+### Options
+
+| Option     | Type                       | Default | Description                                |
+| ---------- | -------------------------- | ------- | ------------------------------------------ |
+| `debounce` | `MaybeRefOrGetter<number>` | `0`     | Debounce delay in ms (can be reactive)     |
+| `maxWait`  | `MaybeRefOrGetter<number>` | —       | Maximum wait time before forced invocation |
+
+All standard `watch` options (`deep`, `immediate`, `flush`, etc.) are also supported.
+
+### Reactive Debounce Time
+
+The debounce time can be reactive:
+
+```ts
+import { watchDebounced } from '@vueuse/core'
+
+const debounceMs = ref(500)
+
+watchDebounced(
+  source,
+  () => { console.log('changed!') },
+  { debounce: debounceMs },
+)
+
+// Later, change the debounce time
+debounceMs.value = 1000
+```
+
+## How It Works
+
+It's essentially a shorthand for the following code:
+
+```ts
+import { debounceFilter, watchWithFilter } from '@vueuse/core'
+
+watchWithFilter(
+  source,
+  () => { console.log('changed!') },
+  {
+    eventFilter: debounceFilter(500, { maxWait: 1000 }),
+  },
+)
+```
+
+## Type Declarations
+
+```ts
+export interface WatchDebouncedOptions<Immediate>
+  extends WatchOptions<Immediate>, DebounceFilterOptions {
+  debounce?: MaybeRefOrGetter<number>
+}
+export declare function watchDebounced<
+  T extends Readonly<MultiWatchSources>,
+  Immediate extends Readonly<boolean> = false,
+>(
+  sources: [...T],
+  cb: WatchCallback<MapSources<T>, MapOldSources<T, Immediate>>,
+  options?: WatchDebouncedOptions<Immediate>,
+): WatchHandle
+export declare function watchDebounced<
+  T,
+  Immediate extends Readonly<boolean> = false,
+>(
+  source: WatchSource<T>,
+  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
+  options?: WatchDebouncedOptions<Immediate>,
+): WatchHandle
+export declare function watchDebounced<
+  T extends object,
+  Immediate extends Readonly<boolean> = false,
+>(
+  source: T,
+  cb: WatchCallback<T, Immediate extends true ? T | undefined : T>,
+  options?: WatchDebouncedOptions<Immediate>,
+): WatchHandle
+/** @deprecated use `watchDebounced` instead */
+export declare const debouncedWatch: typeof watchDebounced
+```