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/watchImmediate.md

@@ -0,0 +1,44 @@
+---
+category: Watch
+---
+
+# watchImmediate
+
+Shorthand for watching value with `{immediate: true}`
+
+## Usage
+
+Similar to `watch`, but with `{ immediate: true }`
+
+```ts
+import { watchImmediate } from '@vueuse/core'
+
+const obj = ref('vue-use')
+
+// changing the value from some external store/composables
+obj.value = 'VueUse'
+
+watchImmediate(obj, (updated) => {
+  console.log(updated) // Console.log will be logged twice
+})
+```
+
+## Type Declarations
+
+```ts
+export declare function watchImmediate<T extends Readonly<MultiWatchSources>>(
+  source: [...T],
+  cb: WatchCallback<MapSources<T>, MapOldSources<T, true>>,
+  options?: Omit<WatchOptions<true>, "immediate">,
+): WatchHandle
+export declare function watchImmediate<T>(
+  source: WatchSource<T>,
+  cb: WatchCallback<T, T | undefined>,
+  options?: Omit<WatchOptions<true>, "immediate">,
+): WatchHandle
+export declare function watchImmediate<T extends object>(
+  source: T,
+  cb: WatchCallback<T, T | undefined>,
+  options?: Omit<WatchOptions<true>, "immediate">,
+): WatchHandle
+```