feat: implement core Go application with web server

- Add Go modules with required dependencies (Gin, UUID, JWT, etc.)
- Implement main web server with landing page endpoint
- Add comprehensive API endpoints for health and status
- Include proper error handling and request validation
- Set up CORS middleware and security headers

output/docker-compose.prod.yml

@@ -0,0 +1,290 @@
+version: '3.8'
+
+services:
+  # PostgreSQL Database
+  ydn-db:
+    image: postgres:15-alpine
+    container_name: YDN-Prod-DB
+    environment:
+      POSTGRES_DB: ${DB_NAME}
+      POSTGRES_USER: ${DB_USER}
+      POSTGRES_PASSWORD: ${DB_PASSWORD}
+      POSTGRES_INITDB_ARGS: "--encoding=UTF-8 --lc-collate=C --lc-ctype=C"
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
+      - ./backups:/backups
+    networks:
+      - ydn-internal
+    restart: always
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U ${DB_USER} -d ${DB_NAME}"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+    deploy:
+      resources:
+        limits:
+          memory: 1G
+        reservations:
+          memory: 512M
+
+  # Redis for sessions and caching
+  ydn-redis:
+    image: redis:7-alpine
+    container_name: YDN-Prod-Redis
+    command: redis-server --appendonly yes --requirepass ${REDIS_PASSWORD} --maxmemory 256mb --maxmemory-policy allkeys-lru
+    volumes:
+      - redis_data:/data
+    networks:
+      - ydn-internal
+    restart: always
+    healthcheck:
+      test: ["CMD", "redis-cli", "--raw", "incr", "ping"]
+      interval: 10s
+      timeout: 3s
+      retries: 5
+    deploy:
+      resources:
+        limits:
+          memory: 256M
+        reservations:
+          memory: 128M
+
+  # Dolibarr ERP/CRM
+  ydn-dolibarr:
+    image: tuxgasy/dolibarr:latest
+    container_name: YDN-Prod-Dolibarr
+    environment:
+      DOLI_DB_HOST: ydn-db
+      DOLI_DB_USER: ${DB_USER}
+      DOLI_DB_PASSWORD: ${DB_PASSWORD}
+      DOLI_DB_NAME: dolibarr_db
+      DOLI_URL_ROOT: 'https://${DOMAIN}/dolibarr'
+      PHP_INI_DATE_TIMEZONE: UTC
+    volumes:
+      - dolibarr_data:/var/www/documents
+      - dolibarr_html:/var/www/html
+    depends_on:
+      ydn-db:
+        condition: service_healthy
+    networks:
+      - ydn-internal
+    restart: always
+    deploy:
+      resources:
+        limits:
+          memory: 512M
+        reservations:
+          memory: 256M
+
+  # Main Application
+  ydn-app:
+    image: ${DOCKER_REGISTRY}/ydn-app:${VERSION}
+    container_name: YDN-Prod-App
+    environment:
+      APP_ENV: production
+      APP_PORT: 8080
+      APP_HOST: 0.0.0.0
+      
+      DB_HOST: ydn-db
+      DB_PORT: 5432
+      DB_USER: ${DB_USER}
+      DB_PASSWORD: ${DB_PASSWORD}
+      DB_NAME: ${DB_NAME}
+      DB_SSLMODE: require
+      
+      REDIS_HOST: ydn-redis
+      REDIS_PORT: 6379
+      REDIS_PASSWORD: ${REDIS_PASSWORD}
+      REDIS_DB: 0
+      
+      JWT_SECRET: ${JWT_SECRET}
+      
+      STRIPE_PUBLIC_KEY: ${STRIPE_PUBLIC_KEY}
+      STRIPE_SECRET_KEY: ${STRIPE_SECRET_KEY}
+      STRIPE_WEBHOOK_SECRET: ${STRIPE_WEBHOOK_SECRET}
+      STRIPE_PRICE_ID: ${STRIPE_PRICE_ID}
+      
+      OVH_ENDPOINT: ${OVH_ENDPOINT}
+      OVH_APPLICATION_KEY: ${OVH_APPLICATION_KEY}
+      OVH_APPLICATION_SECRET: ${OVH_APPLICATION_SECRET}
+      OVH_CONSUMER_KEY: ${OVH_CONSUMER_KEY}
+      
+      DOLIBARR_URL: https://${DOMAIN}/dolibarr
+      DOLIBARR_API_TOKEN: ${DOLIBARR_API_TOKEN}
+      
+      SMTP_HOST: ${SMTP_HOST}
+      SMTP_PORT: ${SMTP_PORT}
+      SMTP_USER: ${SMTP_USER}
+      SMTP_PASSWORD: ${SMTP_PASSWORD}
+      SMTP_FROM: ${SMTP_FROM}
+      
+      LOG_LEVEL: info
+      LOG_FORMAT: json
+      
+      CORS_ORIGINS: https://${DOMAIN}
+      RATE_LIMIT_REQUESTS: 100
+      RATE_LIMIT_WINDOW: 1m
+    volumes:
+      - app_logs:/app/logs
+    depends_on:
+      ydn-db:
+        condition: service_healthy
+      ydn-redis:
+        condition: service_healthy
+    networks:
+      - ydn-internal
+    restart: always
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8080/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
+    deploy:
+      replicas: 2
+      resources:
+        limits:
+          memory: 512M
+        reservations:
+          memory: 256M
+
+  # Nginx Reverse Proxy with SSL
+  ydn-nginx:
+    image: nginx:alpine
+    container_name: YDN-Prod-Nginx
+    volumes:
+      - ./configs/nginx.prod.conf:/etc/nginx/nginx.conf:ro
+      - ./web/static:/usr/share/nginx/html/static:ro
+      - ./ssl:/etc/nginx/ssl:ro
+      - /var/log/nginx:/var/log/nginx
+    ports:
+      - "80:80"
+      - "443:443"
+    depends_on:
+      - ydn-app
+      - ydn-dolibarr
+    networks:
+      - ydn-internal
+      - ydn-external
+    restart: always
+    deploy:
+      resources:
+        limits:
+          memory: 256M
+        reservations:
+          memory: 128M
+
+  # Database Backup Service
+  ydn-backup:
+    image: postgres:15-alpine
+    container_name: YDN-Prod-Backup
+    environment:
+      PGPASSWORD: ${DB_PASSWORD}
+    volumes:
+      - ./backups:/backups
+      - ./scripts/backup.sh:/backup.sh:ro
+    command: sh -c "chmod +x /backup.sh && crond -f"
+    depends_on:
+      ydn-db:
+        condition: service_healthy
+    networks:
+      - ydn-internal
+    restart: always
+    deploy:
+      resources:
+        limits:
+          memory: 128M
+        reservations:
+          memory: 64M
+
+  # Log Aggregation with Loki (Optional)
+  ydn-loki:
+    image: grafana/loki:latest
+    container_name: YDN-Prod-Loki
+    command: -config.file=/etc/loki/local-config.yaml
+    volumes:
+      - ./configs/loki.yml:/etc/loki/local-config.yaml:ro
+      - loki_data:/loki
+    ports:
+      - "3100:3100"
+    networks:
+      - ydn-internal
+    restart: always
+    profiles:
+      - logging
+
+  # Monitoring with Prometheus
+  ydn-prometheus:
+    image: prom/prometheus:latest
+    container_name: YDN-Prod-Prometheus
+    command:
+      - '--config.file=/etc/prometheus/prometheus.yml'
+      - '--storage.tsdb.path=/prometheus'
+      - '--web.console.libraries=/etc/prometheus/console_libraries'
+      - '--web.console.templates=/etc/prometheus/consoles'
+      - '--storage.tsdb.retention.time=30d'
+      - '--web.enable-lifecycle'
+    volumes:
+      - ./configs/prometheus.prod.yml:/etc/prometheus/prometheus.yml:ro
+      - prometheus_data:/prometheus
+    networks:
+      - ydn-internal
+    restart: always
+    profiles:
+      - monitoring
+    deploy:
+      resources:
+        limits:
+          memory: 1G
+        reservations:
+          memory: 512M
+
+  # Grafana for monitoring
+  ydn-grafana:
+    image: grafana/grafana:latest
+    container_name: YDN-Prod-Grafana
+    environment:
+      GF_SECURITY_ADMIN_PASSWORD: ${GRAFANA_ADMIN_PASSWORD}
+      GF_USERS_ALLOW_SIGN_UP: false
+      GF_SERVER_DOMAIN: ${DOMAIN}
+      GF_SERVER_ROOT_URL: https://${DOMAIN}/grafana/
+    volumes:
+      - grafana_data:/var/lib/grafana
+      - ./configs/grafana/provisioning:/etc/grafana/provisioning:ro
+    networks:
+      - ydn-internal
+    restart: always
+    profiles:
+      - monitoring
+    deploy:
+      resources:
+        limits:
+          memory: 512M
+        reservations:
+          memory: 256M
+
+volumes:
+  postgres_data:
+    driver: local
+  redis_data:
+    driver: local
+  dolibarr_data:
+    driver: local
+  dolibarr_html:
+    driver: local
+  app_logs:
+    driver: local
+  prometheus_data:
+    driver: local
+  grafana_data:
+    driver: local
+  loki_data:
+    driver: local
+
+networks:
+  ydn-internal:
+    driver: bridge
+    internal: true
+  ydn-external:
+    driver: bridge