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/pinia/references/features-plugins.md

@@ -0,0 +1,203 @@
+---
+name: plugins
+description: Extend stores with custom properties, methods, and behavior
+---
+
+# Plugins
+
+Plugins extend all stores with custom properties, methods, or behavior.
+
+## Basic Plugin
+
+```ts
+import { createPinia } from 'pinia'
+
+function SecretPiniaPlugin() {
+  return { secret: 'the cake is a lie' }
+}
+
+const pinia = createPinia()
+pinia.use(SecretPiniaPlugin)
+
+// In any store
+const store = useStore()
+store.secret // 'the cake is a lie'
+```
+
+## Plugin Context
+
+Plugins receive a context object:
+
+```ts
+import { PiniaPluginContext } from 'pinia'
+
+export function myPiniaPlugin(context: PiniaPluginContext) {
+  context.pinia   // pinia instance
+  context.app     // Vue app instance
+  context.store   // store being augmented
+  context.options // store definition options
+}
+```
+
+## Adding Properties
+
+Return an object to add properties (tracked in devtools):
+
+```ts
+pinia.use(() => ({ hello: 'world' }))
+```
+
+Or set directly on store:
+
+```ts
+pinia.use(({ store }) => {
+  store.hello = 'world'
+  // For devtools visibility in dev mode
+  if (process.env.NODE_ENV === 'development') {
+    store._customProperties.add('hello')
+  }
+})
+```
+
+## Adding State
+
+Add to both `store` and `store.$state` for SSR/devtools:
+
+```ts
+import { toRef, ref } from 'vue'
+
+pinia.use(({ store }) => {
+  if (!store.$state.hasOwnProperty('hasError')) {
+    const hasError = ref(false)
+    store.$state.hasError = hasError
+  }
+  store.hasError = toRef(store.$state, 'hasError')
+})
+```
+
+## Adding External Properties
+
+Wrap non-reactive objects with `markRaw()`:
+
+```ts
+import { markRaw } from 'vue'
+import { router } from './router'
+
+pinia.use(({ store }) => {
+  store.router = markRaw(router)
+})
+```
+
+## Custom Store Options
+
+Define custom options consumed by plugins:
+
+```ts
+// Store definition
+defineStore('search', {
+  actions: {
+    searchContacts() { /* ... */ },
+  },
+  debounce: {
+    searchContacts: 300,
+  },
+})
+
+// Plugin reads custom option
+import debounce from 'lodash/debounce'
+
+pinia.use(({ options, store }) => {
+  if (options.debounce) {
+    return Object.keys(options.debounce).reduce((acc, action) => {
+      acc[action] = debounce(store[action], options.debounce[action])
+      return acc
+    }, {})
+  }
+})
+```
+
+For Setup Stores, pass options as third argument:
+
+```ts
+defineStore(
+  'search',
+  () => { /* ... */ },
+  {
+    debounce: { searchContacts: 300 },
+  }
+)
+```
+
+## TypeScript Augmentation
+
+### Custom Properties
+
+```ts
+import 'pinia'
+import type { Router } from 'vue-router'
+
+declare module 'pinia' {
+  export interface PiniaCustomProperties {
+    router: Router
+    hello: string
+  }
+}
+```
+
+### Custom State
+
+```ts
+declare module 'pinia' {
+  export interface PiniaCustomStateProperties<S> {
+    hasError: boolean
+  }
+}
+```
+
+### Custom Options
+
+```ts
+declare module 'pinia' {
+  export interface DefineStoreOptionsBase<S, Store> {
+    debounce?: Partial<Record<keyof StoreActions<Store>, number>>
+  }
+}
+```
+
+## Subscribe in Plugins
+
+```ts
+pinia.use(({ store }) => {
+  store.$subscribe(() => {
+    // React to state changes
+  })
+  store.$onAction(() => {
+    // React to actions
+  })
+})
+```
+
+## Nuxt Plugin
+
+Create a Nuxt plugin to add Pinia plugins:
+
+```ts
+// plugins/myPiniaPlugin.ts
+import { PiniaPluginContext } from 'pinia'
+
+function MyPiniaPlugin({ store }: PiniaPluginContext) {
+  store.$subscribe((mutation) => {
+    console.log(`[🍍 ${mutation.storeId}]: ${mutation.type}`)
+  })
+  return { creationTime: new Date() }
+}
+
+export default defineNuxtPlugin(({ $pinia }) => {
+  $pinia.use(MyPiniaPlugin)
+})
+```
+
+<!--
+Source references:
+- https://pinia.vuejs.org/core-concepts/plugins.html
+-->