fix(skills): remove phantom resource references and fix CoC links (#447)

Remove references to non-existent resource files (references/, assets/,
scripts/, examples/) from 115 skill SKILL.md files. These sections
pointed to directories and files that were never created, causing
confusion when users install skills.

Also fix broken Code of Conduct links in issue templates to use
absolute GitHub URLs instead of relative paths that 404.

plugins/frontend-mobile-development/skills/nextjs-app-router-patterns/SKILL.md

@@ -535,9 +535,3 @@ export async function updateProduct(id: string, data: ProductData) {
 - **Don't fetch in Client Components** - Use Server Components or React Query
 - **Don't over-nest layouts** - Each layout adds to the component tree
 - **Don't ignore loading states** - Always provide loading.tsx or Suspense
-
-## Resources
-
-- [Next.js App Router Documentation](https://nextjs.org/docs/app)
-- [Server Components RFC](https://github.com/reactjs/rfcs/blob/main/text/0188-server-components.md)
-- [Vercel Templates](https://vercel.com/templates/next.js)

plugins/frontend-mobile-development/skills/react-native-architecture/SKILL.md

@@ -664,10 +664,3 @@ eas update --branch production --message "Bug fixes"
 - **Don't ignore platform differences** - Test on both iOS and Android
 - **Don't store secrets in code** - Use environment variables
 - **Don't skip error boundaries** - Mobile crashes are unforgiving
-
-## Resources
-
-- [Expo Documentation](https://docs.expo.dev/)
-- [Expo Router](https://docs.expo.dev/router/introduction/)
-- [React Native Performance](https://reactnative.dev/docs/performance)
-- [FlashList](https://shopify.github.io/flash-list/)

plugins/frontend-mobile-development/skills/react-state-management/SKILL.md

@@ -428,10 +428,3 @@ const todosSlice = createSlice({
   },
 });
 ```
-
-## Resources
-
-- [Redux Toolkit Documentation](https://redux-toolkit.js.org/)
-- [Zustand GitHub](https://github.com/pmndrs/zustand)
-- [Jotai Documentation](https://jotai.org/)
-- [TanStack Query](https://tanstack.com/query)

plugins/frontend-mobile-development/skills/tailwind-design-system/SKILL.md

@@ -864,11 +864,3 @@ Define reusable custom utilities:
 - **Don't use arbitrary values** - Extend `@theme` instead
 - **Don't hardcode colors** - Use semantic tokens
 - **Don't forget dark mode** - Test both themes
-
-## Resources
-
-- [Tailwind CSS v4 Documentation](https://tailwindcss.com/docs)
-- [Tailwind v4 Beta Announcement](https://tailwindcss.com/blog/tailwindcss-v4-beta)
-- [CVA Documentation](https://cva.style/docs)
-- [shadcn/ui](https://ui.shadcn.com/)
-- [Radix Primitives](https://www.radix-ui.com/primitives)