feat(01-01): Next.js app + Docker Compose stack with network segmentation

- Next.js 15 app with Tailwind CSS v4, standalone output for Docker
- Root layout with de locale, page with Tessera placeholder
- Multi-stage Dockerfile for web with monorepo root context
- Docker Compose with 4 services: traefik, web, api, db
- Three segregated networks: frontend-net, backend-net, data-net (internal)
- Traefik v2.11 reverse proxy routing / to web, /api to api
- API strip prefix middleware for clean routing
- PostgreSQL 16-alpine with health checks and named volume
- Fixed API Dockerfile for pnpm monorepo node_modules structure
- Fixed Next.js standalone path for monorepo (apps/web/server.js)
- Fixed Traefik Docker API version compatibility
- Network segmentation: web NOT on data-net, api NOT on frontend-net

apps/web/Dockerfile

@@ -0,0 +1,29 @@
+FROM node:24-alpine AS base
+RUN corepack enable && corepack prepare pnpm@9 --activate
+
+FROM base AS deps
+WORKDIR /app
+COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
+COPY apps/web/package.json ./apps/web/
+COPY packages/shared/package.json ./packages/shared/
+RUN pnpm install --frozen-lockfile --filter=@tessera/web...
+
+FROM base AS builder
+WORKDIR /app
+COPY --from=deps /app/ ./
+COPY apps/web/ ./apps/web/
+COPY packages/shared/ ./packages/shared/
+COPY tsconfig.base.json ./
+RUN pnpm --filter=@tessera/web build
+
+FROM node:24-alpine AS runner
+WORKDIR /app
+ENV NODE_ENV=production
+RUN addgroup --system --gid 1001 nodejs && \
+    adduser --system --uid 1001 nextjs
+COPY --from=builder /app/apps/web/public ./apps/web/public
+COPY --from=builder --chown=nextjs:nodejs /app/apps/web/.next/standalone ./
+COPY --from=builder --chown=nextjs:nodejs /app/apps/web/.next/static ./apps/web/.next/static
+USER nextjs
+EXPOSE 3000
+CMD ["node", "apps/web/server.js"]

apps/web/next.config.ts

@@ -0,0 +1,7 @@
+import type { NextConfig } from 'next';
+
+const nextConfig: NextConfig = {
+  output: 'standalone' as const,
+};
+
+export default nextConfig;

apps/web/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "@tessera/web",
+  "version": "0.0.1",
+  "private": true,
+  "scripts": {
+    "dev": "next dev --turbopack",
+    "build": "next build",
+    "start": "next start",
+    "type-check": "tsc --noEmit"
+  },
+  "dependencies": {
+    "next": "^15.3.0",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0"
+  },
+  "devDependencies": {
+    "tailwindcss": "^4.0.0",
+    "@tailwindcss/postcss": "^4.0.0",
+    "postcss": "^8.0.0",
+    "typescript": "^5.5.0",
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0"
+  }
+}

apps/web/postcss.config.mjs

@@ -0,0 +1,8 @@
+/** @type {import('postcss-load-config').Config} */
+const config = {
+  plugins: {
+    "@tailwindcss/postcss": {},
+  },
+};
+
+export default config;

apps/web/src/app/globals.css

@@ -0,0 +1 @@
+@import "tailwindcss";

apps/web/src/app/layout.tsx

@@ -0,0 +1,21 @@
+import type { Metadata } from 'next';
+import './globals.css';
+
+export const metadata: Metadata = {
+  title: 'Tessera',
+  description: 'Modulare Workflow-Plattform',
+};
+
+export default function RootLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  return (
+    <html lang="de">
+      <body className="antialiased">
+        {children}
+      </body>
+    </html>
+  );
+}

apps/web/src/app/page.tsx

@@ -0,0 +1,10 @@
+export default function Home() {
+  return (
+    <main className="flex min-h-screen flex-col items-center justify-center">
+      <h1 className="text-4xl font-bold">Tessera</h1>
+      <p className="mt-4 text-lg text-gray-600">
+        Portal wird geladen...
+      </p>
+    </main>
+  );
+}

apps/web/tsconfig.json

@@ -0,0 +1,18 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "jsx": "preserve",
+    "lib": ["dom", "dom.iterable", "esnext"],
+    "module": "esnext",
+    "moduleResolution": "bundler",
+    "allowJs": true,
+    "noEmit": true,
+    "incremental": true,
+    "plugins": [{ "name": "next" }],
+    "paths": {
+      "@/*": ["./src/*"]
+    }
+  },
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
+  "exclude": ["node_modules"]
+}