feat(api): support remote image URL downloading in chat completion

feat(i2v): enhance image-to-video documentation and single/dual frame support

feat(generation): handle media generation failure status

feat(browser): replace playwright with nodriver for captcha service

feat: 触发429自动禁用和解禁

fix: 图片模型多图支持、重置错误计数

fix: 错误次数计数、调试配置持久化、用量统计计算、日志输出

fix：修复图片输出格式

feat：flow2api初版