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/useMemory.md

@@ -0,0 +1,70 @@
+---
+category: Browser
+---
+
+# useMemory
+
+Reactive Memory Info.
+
+## Usage
+
+```ts
+import { useMemory } from '@vueuse/core'
+
+const { isSupported, memory } = useMemory()
+```
+
+## Type Declarations
+
+```ts
+/**
+ * Performance.memory
+ *
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/Performance/memory
+ */
+export interface MemoryInfo {
+  /**
+   * The maximum size of the heap, in bytes, that is available to the context.
+   */
+  readonly jsHeapSizeLimit: number
+  /**
+   *  The total allocated heap size, in bytes.
+   */
+  readonly totalJSHeapSize: number
+  /**
+   * The currently active segment of JS heap, in bytes.
+   */
+  readonly usedJSHeapSize: number
+  [Symbol.toStringTag]: "MemoryInfo"
+}
+export interface UseMemoryOptions extends ConfigurableScheduler {
+  /**
+   * Start the timer immediately
+   *
+   * @deprecated Please use `scheduler` option instead
+   * @default true
+   */
+  immediate?: boolean
+  /**
+   * Execute the callback immediately after calling `resume`
+   *
+   * @deprecated Please use `scheduler` option instead
+   * @default false
+   */
+  immediateCallback?: boolean
+  /** @deprecated Please use `scheduler` option instead */
+  interval?: number
+}
+export interface UseMemoryReturn extends Supportable {
+  memory: Ref<MemoryInfo | undefined>
+}
+/**
+ * Reactive Memory Info.
+ *
+ * @see https://vueuse.org/useMemory
+ * @param options
+ *
+ * @__NO_SIDE_EFFECTS__
+ */
+export declare function useMemory(options?: UseMemoryOptions): UseMemoryReturn
+```