PORT=3000 DATABASE_URL="mysql://ai_study_user:ai_study_password@localhost:3306/ai_study" REDIS_HOST=localhost REDIS_PORT=6379 AI_PROVIDER=mock AI_API_KEY= AI_BASE_URL= JWT_SECRET=change_me_in_production NODE_ENV=development ENABLE_SWAGGER=true SWAGGER_USER=admin SWAGGER_PASSWORD=change_me