feat(video): 事务化切换与前端统一编排，增强视频输入格式支持

- 后端：切换事务+transition_id，/stream/mode 返回 switching/transition_id 与实际 codec

- 事件：新增 mode_switching/mode_ready，config/webrtc_ready/mode_changed 关联事务

- 编码/格式：扩展 NV21/NV16/NV24/RGB/BGR 输入与转换链路，RKMPP direct input 优化

- 前端：useVideoSession 统一切换，失败回退真实切回 MJPEG，菜单格式同步修复

- 清理：useVideoStream 降级为 MJPEG-only

src/atx/mod.rs

@@ -52,8 +52,8 @@ mod wol;
 pub use controller::{AtxController, AtxControllerConfig};
 pub use executor::timing;
 pub use types::{
-    ActiveLevel, AtxAction, AtxDevices, AtxDriverType, AtxKeyConfig, AtxLedConfig,
-    AtxPowerRequest, AtxState, PowerStatus,
+    ActiveLevel, AtxAction, AtxDevices, AtxDriverType, AtxKeyConfig, AtxLedConfig, AtxPowerRequest,
+    AtxState, PowerStatus,
 };
 pub use wol::send_wol;