feat(tests): add comprehensive unit, integration, and e2e tests for API and database functionality

- Implemented end-to-end tests for API health checks, performance, behavior, and documentation.
- Created integration tests for database connection, CRUD operations, transactions, and connection pool management.
- Developed unit tests for configuration loading, environment variable handling, validation, default values, and helper functions.
- Established a test setup with environment management and basic usage examples for the testing framework.

templates/project/.env.example.raw

@@ -0,0 +1,58 @@
+# 应用配置
+APP_MODE=development
+APP_BASE_URI=http://localhost:8080
+
+# HTTP 服务配置
+HTTP_PORT=8080
+HTTP_HOST=0.0.0.0
+
+# 数据库配置
+DB_HOST=localhost
+DB_PORT=5432
+DB_NAME={{.ProjectName}}
+DB_USER=postgres
+DB_PASSWORD=password
+DB_SSL_MODE=disable
+DB_MAX_CONNECTIONS=25
+DB_MAX_IDLE_CONNECTIONS=5
+DB_CONNECTION_LIFETIME=5m
+
+# Redis 配置
+REDIS_HOST=localhost
+REDIS_PORT=6379
+REDIS_PASSWORD=
+REDIS_DB=0
+
+# JWT 配置
+JWT_SECRET_KEY=your-secret-key-here
+JWT_EXPIRES_TIME=168h
+
+# HashIDs 配置
+HASHIDS_SALT=your-salt-here
+
+# 日志配置
+LOG_LEVEL=info
+LOG_FORMAT=json
+
+# 文件上传配置
+UPLOAD_MAX_SIZE=10MB
+UPLOAD_PATH=./uploads
+
+# 邮件配置
+SMTP_HOST=smtp.gmail.com
+SMTP_PORT=587
+SMTP_USER=
+SMTP_PASSWORD=
+
+# 第三方服务配置
+REDIS_URL=redis://localhost:6379/0
+DATABASE_URL=postgres://postgres:password@localhost:5432/{{.ProjectName}}?sslmode=disable
+
+# 开发配置
+ENABLE_SWAGGER=true
+ENABLE_CORS=true
+DEBUG_MODE=true
+
+# 监控配置
+ENABLE_METRICS=false
+METRICS_PORT=9090