feat: add configurable verification and redemption codes

docs/database.md

@@ -594,7 +594,8 @@ VALUES
 ### 7.2 默认系统配置
 ```sql
 INSERT INTO system_config (key, value, description) VALUES
-('features', '{"registration_enabled": true, "api_key_enabled": true, "anonymous_upload_enabled": true, "email_verification_required": true}', '功能开关'),
+('features', '{"registration_enabled": true, "api_key_enabled": true, "anonymous_upload_enabled": true}', '功能开关'),
+('auth', '{"email_verification_required": true}', '认证功能开关'),
 ('rate_limits', '{"anonymous_per_minute": 10, "anonymous_units_per_day": 10, "user_per_minute": 60, "api_key_per_minute": 100}', '速率限制默认值'),
 ('file_limits', '{"max_image_pixels": 40000000}', '图片安全限制（像素上限等）'),
 ('mail', '{"enabled": true, "provider": "custom", "from": "noreply@example.com", "from_name": "ImageForge"}', '邮件服务配置（密码加密存储）');