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/watchTriggerable.md

@@ -0,0 +1,98 @@
+---
+category: Watch
+---
+
+# watchTriggerable
+
+Watch that can be triggered manually
+
+## Usage
+
+A `watch` wrapper that supports manual triggering of `WatchCallback`, which returns an additional `trigger` to execute a `WatchCallback` immediately.
+
+```ts
+import { watchTriggerable } from '@vueuse/core'
+import { nextTick, shallowRef } from 'vue'
+
+const source = shallowRef(0)
+
+const { trigger, ignoreUpdates } = watchTriggerable(
+  source,
+  v => console.log(`Changed to ${v}!`),
+)
+
+source.value = 'bar'
+await nextTick() // logs: Changed to bar!
+
+// Execution of WatchCallback via `trigger` does not require waiting
+trigger() // logs: Changed to bar!
+```
+
+### `onCleanup`
+
+When you want to manually call a `watch` that uses the onCleanup parameter; simply taking the `WatchCallback` out and calling it doesn't make it easy to implement the `onCleanup` parameter.
+
+Using `watchTriggerable` will solve this problem.
+
+```ts
+import { watchTriggerable } from '@vueuse/core'
+import { shallowRef } from 'vue'
+
+const source = shallowRef(0)
+
+const { trigger } = watchTriggerable(
+  source,
+  async (v, _, onCleanup) => {
+    let canceled = false
+    onCleanup(() => canceled = true)
+
+    await new Promise(resolve => setTimeout(resolve, 500))
+    if (canceled)
+      return
+
+    console.log(`The value is "${v}"\n`)
+  },
+)
+
+source.value = 1 // no log
+await trigger() // logs (after 500 ms): The value is "1"
+```
+
+## Type Declarations
+
+```ts
+export interface WatchTriggerableReturn<
+  FnReturnT = void,
+> extends WatchIgnorableReturn {
+  /** Execute `WatchCallback` immediately */
+  trigger: () => FnReturnT
+}
+type OnCleanup = (cleanupFn: () => void) => void
+export type WatchTriggerableCallback<V = any, OV = any, R = void> = (
+  value: V,
+  oldValue: OV,
+  onCleanup: OnCleanup,
+) => R
+export declare function watchTriggerable<
+  T extends Readonly<MultiWatchSources>,
+  FnReturnT,
+>(
+  sources: [...T],
+  cb: WatchTriggerableCallback<
+    MapSources<T>,
+    MapOldSources<T, true>,
+    FnReturnT
+  >,
+  options?: WatchWithFilterOptions<boolean>,
+): WatchTriggerableReturn<FnReturnT>
+export declare function watchTriggerable<T, FnReturnT>(
+  source: WatchSource<T>,
+  cb: WatchTriggerableCallback<T, T | undefined, FnReturnT>,
+  options?: WatchWithFilterOptions<boolean>,
+): WatchTriggerableReturn<FnReturnT>
+export declare function watchTriggerable<T extends object, FnReturnT>(
+  source: T,
+  cb: WatchTriggerableCallback<T, T | undefined, FnReturnT>,
+  options?: WatchWithFilterOptions<boolean>,
+): WatchTriggerableReturn<FnReturnT>
+```