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/useSubject.md

@@ -0,0 +1,52 @@
+---
+category: '@RxJS'
+---
+
+# useSubject
+
+Bind an RxJS [`Subject`](https://rxjs.dev/guide/subject) to a `ref` and propagate value changes both ways.
+
+## Usage
+
+<!-- TODO: import rxjs error if enable twoslash -->
+
+```ts no-twoslash
+import { useSubject } from '@vueuse/rxjs'
+import { Subject } from 'rxjs'
+
+const subject = new Subject()
+
+// setup()
+const subjectRef = useSubject(subject)
+```
+
+If you want to add custom error handling to a Subject that might error, you can supply an optional `onError` configuration. Without this, RxJS will treat any error in the supplied observable as an "unhandled error" and it will be thrown in a new call stack and reported to `window.onerror` (or `process.on('error')` if you happen to be in node).
+
+```ts no-twoslash
+import { useSubject } from '@vueuse/rxjs'
+import { Subject } from 'rxjs'
+
+const subject = new Subject()
+
+// setup()
+const subjectRef = useSubject(subject, {
+  onError: (err) => {
+    console.log(err.message) // "oops"
+  },
+},)
+```
+
+## Type Declarations
+
+```ts
+export interface UseSubjectOptions<I = undefined>
+  extends Omit<UseObservableOptions<I>, "initialValue"> {}
+export declare function useSubject<H>(
+  subject: BehaviorSubject<H>,
+  options?: UseSubjectOptions,
+): Ref<H>
+export declare function useSubject<H>(
+  subject: Subject<H>,
+  options?: UseSubjectOptions,
+): Ref<H | undefined>
+```