Initial project setup: Next.js frontend + .NET 9 backend

- Frontend: Next.js 16 + shadcn/ui + Tailwind CSS 4
- Backend: .NET 9 Web API with Npgsql health check
- Docker Compose for prod and dev environments
- Woodpecker CI pipeline for auto-deploy
- Health check endpoints for E2E testing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

deploy/docker-compose.dev.yml

@@ -0,0 +1,28 @@
+services:
+  gb-dev-frontend:
+    build: ../frontend
+    container_name: gb-dev-frontend
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:3200:3000"
+    environment:
+      - NODE_ENV=production
+      - INTERNAL_API_URL=http://gb-dev-backend:5000
+    networks:
+      - app-network
+
+  gb-dev-backend:
+    build: ../backend
+    container_name: gb-dev-backend
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:5200:5000"
+    environment:
+      - ASPNETCORE_ENVIRONMENT=Development
+      - ConnectionStrings__Default=Host=postgres;Port=5432;Database=dev_db;Username=dev_user;Password=dev_pass_vB6nM3qP8yW2rT9k
+    networks:
+      - app-network
+
+networks:
+  app-network:
+    external: true

deploy/docker-compose.prod.yml

@@ -0,0 +1,28 @@
+services:
+  gb-prod-frontend:
+    build: ../frontend
+    container_name: gb-prod-frontend
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:3100:3000"
+    environment:
+      - NODE_ENV=production
+      - INTERNAL_API_URL=http://gb-prod-backend:5000
+    networks:
+      - app-network
+
+  gb-prod-backend:
+    build: ../backend
+    container_name: gb-prod-backend
+    restart: unless-stopped
+    ports:
+      - "127.0.0.1:5100:5000"
+    environment:
+      - ASPNETCORE_ENVIRONMENT=Production
+      - ConnectionStrings__Default=Host=postgres;Port=5432;Database=prod_db;Username=prod_user;Password=prod_pass_kL9mN2pQ7xR8sT4v
+    networks:
+      - app-network
+
+networks:
+  app-network:
+    external: true