Upgrade to Next.js 16 with Turbopack and Contentlayer2

- Upgraded Next.js to v16, React to v19
- Migrated from contentlayer to contentlayer2
- Migrated to Turbopack by decoupling Contentlayer from webpack
- Updated all page components to handle async params (Next.js 15+ breaking change)
- Changed package.json to type: module and renamed config files to .cjs
- Updated README with current tech stack and article creation instructions
- Fixed tag encoding issue (removed double encoding)
- All security vulnerabilities resolved (npm audit: 0 vulnerabilities)

next-env.d.ts

@@ -1,5 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
+import "./.next/dev/types/routes.d.ts";
 
 // NOTE: This file should not be edited
-// see https://nextjs.org/docs/basic-features/typescript for more information.
+// see https://nextjs.org/docs/app/api-reference/config/typescript for more information.