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/createGlobalState.md

@@ -0,0 +1,95 @@
+---
+category: State
+related: createSharedComposable
+---
+
+# createGlobalState
+
+Keep states in the global scope to be reusable across Vue instances.
+
+## Usage
+
+### Without Persistence (Store in Memory)
+
+```ts
+// store.ts
+import { createGlobalState } from '@vueuse/core'
+import { shallowRef } from 'vue'
+
+export const useGlobalState = createGlobalState(
+  () => {
+    const count = shallowRef(0)
+    return { count }
+  }
+)
+```
+
+A bigger example:
+
+```ts
+// store.ts
+import { createGlobalState } from '@vueuse/core'
+import { computed, shallowRef } from 'vue'
+
+export const useGlobalState = createGlobalState(
+  () => {
+    // state
+    const count = shallowRef(0)
+
+    // getters
+    const doubleCount = computed(() => count.value * 2)
+
+    // actions
+    function increment() {
+      count.value++
+    }
+
+    return { count, doubleCount, increment }
+  }
+)
+```
+
+### With Persistence
+
+Store in `localStorage` with `useStorage`:
+
+```ts twoslash include store
+// store.ts
+import { createGlobalState, useStorage } from '@vueuse/core'
+
+export const useGlobalState = createGlobalState(
+  () => useStorage('vueuse-local-storage', 'initialValue'),
+)
+```
+
+```ts
+// @filename: store.ts
+// @include: store
+// ---cut---
+// component.ts
+import { useGlobalState } from './store'
+
+export default defineComponent({
+  setup() {
+    const state = useGlobalState()
+    return { state }
+  },
+})
+```
+
+## Type Declarations
+
+```ts
+export type CreateGlobalStateReturn<Fn extends AnyFn = AnyFn> = Fn
+/**
+ * Keep states in the global scope to be reusable across Vue instances.
+ *
+ * @see https://vueuse.org/createGlobalState
+ * @param stateFactory A factory function to create the state
+ *
+ * @__NO_SIDE_EFFECTS__
+ */
+export declare function createGlobalState<Fn extends AnyFn>(
+  stateFactory: Fn,
+): CreateGlobalStateReturn<Fn>
+```