Initial project structure: Next.js 15 + TypeScript + Drizzle ORM

- Next.js 15 with App Router, TypeScript, Tailwind CSS
- Directory structure per LegalAI architecture plan
- Docker Compose setup (PostgreSQL 16, Meilisearch, App)
- Drizzle ORM with base schema (tenants, users, norms, decisions)
- AI abstraction layer structure (Vercel AI SDK)
- Normen-Engine with Quellenrang hierarchy
- Search abstraction layer
- Auth placeholder (NextAuth.js)

Co-Authored-By: Paperclip <noreply@paperclip.ing>

drizzle.config.ts

@@ -0,0 +1,10 @@
+import { defineConfig } from 'drizzle-kit';
+
+export default defineConfig({
+  schema: './src/lib/db/schema.ts',
+  out: './drizzle',
+  dialect: 'postgresql',
+  dbCredentials: {
+    url: process.env.DATABASE_URL!,
+  },
+});