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/vercel-composition-patterns/rules/react19-no-forwardref.md

@@ -0,0 +1,42 @@
+---
+title: React 19 API Changes
+impact: MEDIUM
+impactDescription: cleaner component definitions and context usage
+tags: react19, refs, context, hooks
+---
+
+## React 19 API Changes
+
+> **⚠️ React 19+ only.** Skip this if you're on React 18 or earlier.
+
+In React 19, `ref` is now a regular prop (no `forwardRef` wrapper needed), and `use()` replaces `useContext()`.
+
+**Incorrect (forwardRef in React 19):**
+
+```tsx
+const ComposerInput = forwardRef<TextInput, Props>((props, ref) => {
+  return <TextInput ref={ref} {...props} />
+})
+```
+
+**Correct (ref as a regular prop):**
+
+```tsx
+function ComposerInput({ ref, ...props }: Props & { ref?: React.Ref<TextInput> }) {
+  return <TextInput ref={ref} {...props} />
+}
+```
+
+**Incorrect (useContext in React 19):**
+
+```tsx
+const value = useContext(MyContext)
+```
+
+**Correct (use instead of useContext):**
+
+```tsx
+const value = use(MyContext)
+```
+
+`use()` can also be called conditionally, unlike `useContext()`.