Extract request_auth_channel as a distinct routing dimension to distinguish between api_key and bearer_like authentication methods. This improves routing clarity by decoupling authentication mechanism from route classification.
将 gateway 内部的 model-fetch、provider-transport、scheduler-core、 usage-runtime、video-tasks-core 模块提取为独立 crate；重构 gateway 内部模块结构（state/router/cache/data/query 等）；移除大量遗留模块 文件；新增 systemd 二进制部署骨架及相关文档；更新前端 usage 相关 API 和组件。
MMEXA