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/computedEager.md

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+---
+category: Reactivity
+alias: eagerComputed
+---
+
+# computedEager
+
+Eager computed without lazy evaluation.
+
+::: info
+This function will be removed in future version.
+:::
+
+::: tip
+Note💡: If you are using Vue 3.4+, you can use `computed` right away, you no longer need this function.
+In Vue 3.4+, if the computed new value does not change, `computed`, `effect`, `watch`, `watchEffect`, `render` dependencies will not be triggered.
+See: https://github.com/vuejs/core/pull/5912
+:::
+
+Learn more at [Vue: When a computed property can be the wrong tool](https://dev.to/linusborg/vue-when-a-computed-property-can-be-the-wrong-tool-195j).
+
+- Use `computed()` when you have a complex calculation going on, which can actually profit from caching and lazy evaluation and should only be (re-)calculated if really necessary.
+- Use `computedEager()` when you have a simple operation, with a rarely changing return value – often a boolean.
+
+## Usage
+
+```ts
+import { computedEager } from '@vueuse/core'
+
+const todos = ref([])
+const hasOpenTodos = computedEager(() => !!todos.length)
+
+console.log(hasOpenTodos.value) // false
+toTodos.value.push({ title: 'Learn Vue' })
+console.log(hasOpenTodos.value) // true
+```
+
+## Type Declarations
+
+```ts
+export type ComputedEagerOptions = WatchOptionsBase
+export type ComputedEagerReturn<T = any> = Readonly<ShallowRef<T>>
+/**
+ *
+ * @deprecated This function will be removed in future version.
+ *
+ * Note: If you are using Vue 3.4+, you can straight use computed instead.
+ * Because in Vue 3.4+, if computed new value does not change,
+ * computed, effect, watch, watchEffect, render dependencies will not be triggered.
+ * refer: https://github.com/vuejs/core/pull/5912
+ *
+ * @param fn effect function
+ * @param options WatchOptionsBase
+ * @returns readonly shallowRef
+ */
+export declare function computedEager<T>(
+  fn: () => T,
+  options?: ComputedEagerOptions,
+): ComputedEagerReturn<T>
+/** @deprecated use `computedEager` instead */
+export declare const eagerComputed: typeof computedEager
+```