feat: 新增 Amlogic AMLENC 硬件编码支持

- 新增动态加载及 ABI 校验的 AMLENC H.264/H.265 编码器
- 注册 Amlogic 后端并扩展编码器自检
- 并行执行 MJPEG 解码与 AMLENC 编码
- 复用 NV12 缓冲区并移除冗余帧初始化
- 优化低延迟帧分发及 RTCP 关键帧恢复
- 动态调整 AMLENC 码率尚未完成，效果不佳

src/web/routes.rs

@@ -76,6 +76,7 @@ pub fn create_router(state: Arc<AppState>) -> Router {
         .route("/stream/mode", post(handlers::stream_mode_set))
         .route("/stream/bitrate", post(handlers::stream_set_bitrate))
         .route("/stream/codecs", get(handlers::stream_codecs_list))
+        .route("/video/codecs", get(handlers::stream_codecs_list))
         .route("/stream/constraints", get(handlers::stream_constraints_get))
         .route(
             "/video/encoder/self-check",