refactor(hwcodec): 简化 hwcodec 库以适配 IP-KVM 场景

移除 IP-KVM 场景不需要的功能模块:
- 移除 VRAM 模块 (GPU 显存直接编解码)
- 移除 Mux 模块 (视频混流)
- 移除 macOS/Android 平台支持
- 移除外部 SDK 依赖 (~9MB)
- 移除开发工具和示例程序

简化解码器为仅支持 MJPEG (采集卡输出格式)
简化 NVIDIA 检测代码 (使用 dlopen 替代 SDK)
更新版本号至 0.8.0
更新相关技术文档

libs/hwcodec/Cargo.toml

@@ -1,13 +1,11 @@
 [package]
 name = "hwcodec"
-version = "0.7.1"
+version = "0.8.0"
 edition = "2021"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+description = "Hardware video codec for IP-KVM (Windows/Linux)"
 
 [features]
 default = []
-vram = []
 
 [dependencies]
 log = "0.4"
@@ -21,9 +19,3 @@ bindgen = "0.59"
 
 [dev-dependencies]
 env_logger = "0.10"
-rand = "0.8"
-
-[target.'cfg(target_os="windows")'.dev-dependencies]
-capture = { path = "dev/capture" }
-render = { path = "dev/render" }
-tool = { path = "dev/tool" }