feat: Complete fleet — 94 skills across 10+ domains

Pulled ALL skills from 15 source repositories:
- anthropics/skills: 16 (docs, design, MCP, testing)
- obra/superpowers: 14 (TDD, debugging, agents, planning)
- coreyhaines31/marketingskills: 25 (marketing, CRO, SEO, growth)
- better-auth/skills: 5 (auth patterns)
- vercel-labs/agent-skills: 5 (React, design, Vercel)
- antfu/skills: 16 (Vue, Vite, Vitest, pnpm, Turborepo)
- Plus 13 individual skills from various repos

Mosaic Stack is not limited to coding — the Orchestrator and
subagents serve coding, business, design, marketing, writing,
logistics, analysis, and more.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/vueuse-functions/references/useMutationObserver.md

@@ -0,0 +1,62 @@
+---
+category: Elements
+---
+
+# useMutationObserver
+
+Watch for changes being made to the DOM tree. [MutationObserver MDN](https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver)
+
+## Usage
+
+```vue
+<script setup lang="ts">
+import { useMutationObserver } from '@vueuse/core'
+import { ref, useTemplateRef } from 'vue'
+
+const el = useTemplateRef('el')
+const messages = ref([])
+
+useMutationObserver(el, (mutations) => {
+  if (mutations[0])
+    messages.value.push(mutations[0].attributeName)
+}, {
+  attributes: true,
+})
+</script>
+
+<template>
+  <div ref="el">
+    Hello VueUse
+  </div>
+</template>
+```
+
+## Type Declarations
+
+```ts
+export interface UseMutationObserverOptions
+  extends MutationObserverInit,
+    ConfigurableWindow {}
+/**
+ * Watch for changes being made to the DOM tree.
+ *
+ * @see https://vueuse.org/useMutationObserver
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver MutationObserver MDN
+ * @param target
+ * @param callback
+ * @param options
+ */
+export declare function useMutationObserver(
+  target:
+    | MaybeComputedElementRef
+    | MaybeComputedElementRef[]
+    | MaybeRefOrGetter<MaybeElement[]>,
+  callback: MutationCallback,
+  options?: UseMutationObserverOptions,
+): {
+  isSupported: ComputedRef<boolean>
+  stop: () => void
+  takeRecords: () => MutationRecord[] | undefined
+}
+export type UseMutationObserverReturn = ReturnType<typeof useMutationObserver>
+```