feat(01-01): Next.js 15 project with Docker Compose dev environment

- Next.js 15 with App Router, TypeScript, Tailwind CSS (v4), ESLint
- docker-compose.yml with PostgreSQL 16, Redis 7, and app service
- Dockerfile (Node 20 alpine) for containerized development
- .env and .env.example with DATABASE_URL, DATABASE_URL_LOCAL, REDIS_URL
- src/app/page.tsx updated to render NetForge heading
- All three services start healthy with docker compose up -d

next-env.d.ts

@@ -0,0 +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/app/api-reference/config/typescript for more information.