feat: 添加 RustDesk 协议支持和项目文档

- 新增 RustDesk 模块，支持与 RustDesk 客户端连接
  - 实现会合服务器协议和 P2P 连接
  - 支持 NaCl 加密和密钥交换
  - 添加视频帧和 HID 事件适配器
- 添加 Protobuf 协议定义 (message.proto, rendezvous.proto)
- 新增完整项目文档
  - 各功能模块文档 (video, hid, msd, otg, webrtc 等)
  - hwcodec 和 RustDesk 协议技术报告
  - 系统架构和技术栈文档
- 更新 Web 前端 RustDesk 配置界面和 API

docs/report/rustdesk/05-message-format.md

@@ -0,0 +1,574 @@
+# 消息格式定义
+
+## 概述
+
+RustDesk 使用 Protocol Buffers (protobuf) 定义所有网络消息格式。主要有两个 proto 文件：
+
+- `rendezvous.proto` - Rendezvous/Relay 服务器通信消息
+- `message.proto` - 客户端之间通信消息
+
+## Rendezvous 消息 (rendezvous.proto)
+
+### 顶层消息
+
+```protobuf
+message RendezvousMessage {
+  oneof union {
+    RegisterPeer register_peer = 6;
+    RegisterPeerResponse register_peer_response = 7;
+    PunchHoleRequest punch_hole_request = 8;
+    PunchHole punch_hole = 9;
+    PunchHoleSent punch_hole_sent = 10;
+    PunchHoleResponse punch_hole_response = 11;
+    FetchLocalAddr fetch_local_addr = 12;
+    LocalAddr local_addr = 13;
+    ConfigUpdate configure_update = 14;
+    RegisterPk register_pk = 15;
+    RegisterPkResponse register_pk_response = 16;
+    SoftwareUpdate software_update = 17;
+    RequestRelay request_relay = 18;
+    RelayResponse relay_response = 19;
+    TestNatRequest test_nat_request = 20;
+    TestNatResponse test_nat_response = 21;
+    PeerDiscovery peer_discovery = 22;
+    OnlineRequest online_request = 23;
+    OnlineResponse online_response = 24;
+    KeyExchange key_exchange = 25;
+    HealthCheck hc = 26;
+  }
+}
+```
+
+### 注册相关
+
+```protobuf
+// Peer 注册
+message RegisterPeer {
+  string id = 1;      // Peer ID
+  int32 serial = 2;   // 配置序列号
+}
+
+message RegisterPeerResponse {
+  bool request_pk = 2;  // 是否需要注册公钥
+}
+
+// 公钥注册
+message RegisterPk {
+  string id = 1;       // Peer ID
+  bytes uuid = 2;      // 设备 UUID
+  bytes pk = 3;        // Ed25519 公钥
+  string old_id = 4;   // 旧 ID
+}
+
+message RegisterPkResponse {
+  enum Result {
+    OK = 0;
+    UUID_MISMATCH = 2;
+    ID_EXISTS = 3;
+    TOO_FREQUENT = 4;
+    INVALID_ID_FORMAT = 5;
+    NOT_SUPPORT = 6;
+    SERVER_ERROR = 7;
+  }
+  Result result = 1;
+  int32 keep_alive = 2;
+}
+```
+
+### 连接协调相关
+
+```protobuf
+// 连接类型
+enum ConnType {
+  DEFAULT_CONN = 0;
+  FILE_TRANSFER = 1;
+  PORT_FORWARD = 2;
+  RDP = 3;
+  VIEW_CAMERA = 4;
+}
+
+// NAT 类型
+enum NatType {
+  UNKNOWN_NAT = 0;
+  ASYMMETRIC = 1;   // 可打洞
+  SYMMETRIC = 2;    // 需要中转
+}
+
+// Punch Hole 请求
+message PunchHoleRequest {
+  string id = 1;           // 目标 Peer ID
+  NatType nat_type = 2;
+  string licence_key = 3;
+  ConnType conn_type = 4;
+  string token = 5;
+  string version = 6;
+}
+
+// Punch Hole 响应
+message PunchHoleResponse {
+  bytes socket_addr = 1;      // 目标地址
+  bytes pk = 2;               // 公钥（已签名）
+  enum Failure {
+    ID_NOT_EXIST = 0;
+    OFFLINE = 2;
+    LICENSE_MISMATCH = 3;
+    LICENSE_OVERUSE = 4;
+  }
+  Failure failure = 3;
+  string relay_server = 4;
+  oneof union {
+    NatType nat_type = 5;
+    bool is_local = 6;
+  }
+  string other_failure = 7;
+  int32 feedback = 8;
+}
+
+// 服务器转发给被控端
+message PunchHole {
+  bytes socket_addr = 1;      // 控制端地址
+  string relay_server = 2;
+  NatType nat_type = 3;
+}
+
+// 被控端发送给服务器
+message PunchHoleSent {
+  bytes socket_addr = 1;
+  string id = 2;
+  string relay_server = 3;
+  NatType nat_type = 4;
+  string version = 5;
+}
+```
+
+### Relay 相关
+
+```protobuf
+// Relay 请求
+message RequestRelay {
+  string id = 1;
+  string uuid = 2;          // 配对 UUID
+  bytes socket_addr = 3;
+  string relay_server = 4;
+  bool secure = 5;
+  string licence_key = 6;
+  ConnType conn_type = 7;
+  string token = 8;
+}
+
+// Relay 响应
+message RelayResponse {
+  bytes socket_addr = 1;
+  string uuid = 2;
+  string relay_server = 3;
+  oneof union {
+    string id = 4;
+    bytes pk = 5;
+  }
+  string refuse_reason = 6;
+  string version = 7;
+  int32 feedback = 9;
+}
+```
+
+## 会话消息 (message.proto)
+
+### 顶层消息
+
+```protobuf
+message Message {
+  oneof union {
+    SignedId signed_id = 3;
+    PublicKey public_key = 4;
+    TestDelay test_delay = 5;
+    VideoFrame video_frame = 6;
+    LoginRequest login_request = 7;
+    LoginResponse login_response = 8;
+    Hash hash = 9;
+    MouseEvent mouse_event = 10;
+    AudioFrame audio_frame = 11;
+    CursorData cursor_data = 12;
+    CursorPosition cursor_position = 13;
+    uint64 cursor_id = 14;
+    KeyEvent key_event = 15;
+    Clipboard clipboard = 16;
+    FileAction file_action = 17;
+    FileResponse file_response = 18;
+    Misc misc = 19;
+    Cliprdr cliprdr = 20;
+    MessageBox message_box = 21;
+    SwitchSidesResponse switch_sides_response = 22;
+    VoiceCallRequest voice_call_request = 23;
+    VoiceCallResponse voice_call_response = 24;
+    PeerInfo peer_info = 25;
+    PointerDeviceEvent pointer_device_event = 26;
+    Auth2FA auth_2fa = 27;
+    MultiClipboards multi_clipboards = 28;
+  }
+}
+```
+
+### 认证相关
+
+```protobuf
+// ID 和公钥
+message IdPk {
+  string id = 1;
+  bytes pk = 2;
+}
+
+// 密钥交换
+message PublicKey {
+  bytes asymmetric_value = 1;  // X25519 公钥
+  bytes symmetric_value = 2;   // 加密的对称密钥
+}
+
+// 签名的 ID
+message SignedId {
+  bytes id = 1;  // 签名的 IdPk
+}
+
+// 密码哈希挑战
+message Hash {
+  string salt = 1;
+  string challenge = 2;
+}
+
+// 登录请求
+message LoginRequest {
+  string username = 1;
+  bytes password = 2;         // 加密的密码
+  string my_id = 4;
+  string my_name = 5;
+  OptionMessage option = 6;
+  oneof union {
+    FileTransfer file_transfer = 7;
+    PortForward port_forward = 8;
+    ViewCamera view_camera = 15;
+  }
+  bool video_ack_required = 9;
+  uint64 session_id = 10;
+  string version = 11;
+  OSLogin os_login = 12;
+  string my_platform = 13;
+  bytes hwid = 14;
+}
+
+// 登录响应
+message LoginResponse {
+  oneof union {
+    string error = 1;
+    PeerInfo peer_info = 2;
+  }
+  bool enable_trusted_devices = 3;
+}
+
+// 2FA 认证
+message Auth2FA {
+  string code = 1;
+  bytes hwid = 2;
+}
+```
+
+### 视频相关
+
+```protobuf
+// 编码后的视频帧
+message EncodedVideoFrame {
+  bytes data = 1;
+  bool key = 2;     // 是否关键帧
+  int64 pts = 3;    // 时间戳
+}
+
+message EncodedVideoFrames {
+  repeated EncodedVideoFrame frames = 1;
+}
+
+// 视频帧
+message VideoFrame {
+  oneof union {
+    EncodedVideoFrames vp9s = 6;
+    RGB rgb = 7;
+    YUV yuv = 8;
+    EncodedVideoFrames h264s = 10;
+    EncodedVideoFrames h265s = 11;
+    EncodedVideoFrames vp8s = 12;
+    EncodedVideoFrames av1s = 13;
+  }
+  int32 display = 14;  // 显示器索引
+}
+
+// 显示信息
+message DisplayInfo {
+  sint32 x = 1;
+  sint32 y = 2;
+  int32 width = 3;
+  int32 height = 4;
+  string name = 5;
+  bool online = 6;
+  bool cursor_embedded = 7;
+  Resolution original_resolution = 8;
+  double scale = 9;
+}
+```
+
+### 输入相关
+
+```protobuf
+// 鼠标事件
+message MouseEvent {
+  int32 mask = 1;      // 按钮掩码
+  sint32 x = 2;
+  sint32 y = 3;
+  repeated ControlKey modifiers = 4;
+}
+
+// 键盘事件
+message KeyEvent {
+  bool down = 1;       // 按下/释放
+  bool press = 2;      // 单击
+  oneof union {
+    ControlKey control_key = 3;
+    uint32 chr = 4;         // 字符码
+    uint32 unicode = 5;     // Unicode
+    string seq = 6;         // 字符序列
+    uint32 win2win_hotkey = 7;
+  }
+  repeated ControlKey modifiers = 8;
+  KeyboardMode mode = 9;
+}
+
+// 键盘模式
+enum KeyboardMode {
+  Legacy = 0;
+  Map = 1;
+  Translate = 2;
+  Auto = 3;
+}
+
+// 控制键枚举（部分）
+enum ControlKey {
+  Unknown = 0;
+  Alt = 1;
+  Backspace = 2;
+  CapsLock = 3;
+  Control = 4;
+  Delete = 5;
+  // ... 更多按键
+  CtrlAltDel = 100;
+  LockScreen = 101;
+}
+```
+
+### 音频相关
+
+```protobuf
+// 音频格式
+message AudioFormat {
+  uint32 sample_rate = 1;
+  uint32 channels = 2;
+}
+
+// 音频帧
+message AudioFrame {
+  bytes data = 1;  // Opus 编码数据
+}
+```
+
+### 剪贴板相关
+
+```protobuf
+// 剪贴板格式
+enum ClipboardFormat {
+  Text = 0;
+  Rtf = 1;
+  Html = 2;
+  ImageRgba = 21;
+  ImagePng = 22;
+  ImageSvg = 23;
+  Special = 31;
+}
+
+// 剪贴板内容
+message Clipboard {
+  bool compress = 1;
+  bytes content = 2;
+  int32 width = 3;
+  int32 height = 4;
+  ClipboardFormat format = 5;
+  string special_name = 6;
+}
+
+message MultiClipboards {
+  repeated Clipboard clipboards = 1;
+}
+```
+
+### 文件传输相关
+
+```protobuf
+// 文件操作
+message FileAction {
+  oneof union {
+    ReadDir read_dir = 1;
+    FileTransferSendRequest send = 2;
+    FileTransferReceiveRequest receive = 3;
+    FileDirCreate create = 4;
+    FileRemoveDir remove_dir = 5;
+    FileRemoveFile remove_file = 6;
+    ReadAllFiles all_files = 7;
+    FileTransferCancel cancel = 8;
+    FileTransferSendConfirmRequest send_confirm = 9;
+    FileRename rename = 10;
+    ReadEmptyDirs read_empty_dirs = 11;
+  }
+}
+
+// 文件响应
+message FileResponse {
+  oneof union {
+    FileDirectory dir = 1;
+    FileTransferBlock block = 2;
+    FileTransferError error = 3;
+    FileTransferDone done = 4;
+    FileTransferDigest digest = 5;
+    ReadEmptyDirsResponse empty_dirs = 6;
+  }
+}
+
+// 文件传输块
+message FileTransferBlock {
+  int32 id = 1;
+  sint32 file_num = 2;
+  bytes data = 3;
+  bool compressed = 4;
+  uint32 blk_id = 5;
+}
+
+// 文件条目
+message FileEntry {
+  FileType entry_type = 1;
+  string name = 2;
+  bool is_hidden = 3;
+  uint64 size = 4;
+  uint64 modified_time = 5;
+}
+```
+
+### 杂项消息
+
+```protobuf
+message Misc {
+  oneof union {
+    ChatMessage chat_message = 4;
+    SwitchDisplay switch_display = 5;
+    PermissionInfo permission_info = 6;
+    OptionMessage option = 7;
+    AudioFormat audio_format = 8;
+    string close_reason = 9;
+    bool refresh_video = 10;
+    bool video_received = 12;
+    BackNotification back_notification = 13;
+    bool restart_remote_device = 14;
+    // ... 更多选项
+  }
+}
+
+// Peer 信息
+message PeerInfo {
+  string username = 1;
+  string hostname = 2;
+  string platform = 3;
+  repeated DisplayInfo displays = 4;
+  int32 current_display = 5;
+  bool sas_enabled = 6;
+  string version = 7;
+  Features features = 9;
+  SupportedEncoding encoding = 10;
+  SupportedResolutions resolutions = 11;
+  string platform_additions = 12;
+  WindowsSessions windows_sessions = 13;
+}
+
+// 选项消息
+message OptionMessage {
+  enum BoolOption {
+    NotSet = 0;
+    No = 1;
+    Yes = 2;
+  }
+  ImageQuality image_quality = 1;
+  BoolOption lock_after_session_end = 2;
+  BoolOption show_remote_cursor = 3;
+  BoolOption privacy_mode = 4;
+  BoolOption block_input = 5;
+  int32 custom_image_quality = 6;
+  BoolOption disable_audio = 7;
+  BoolOption disable_clipboard = 8;
+  BoolOption enable_file_transfer = 9;
+  SupportedDecoding supported_decoding = 10;
+  int32 custom_fps = 11;
+  // ... 更多选项
+}
+```
+
+## 消息编码
+
+### 长度前缀
+
+TCP 传输时使用长度前缀编码：
+
+```rust
+// hbb_common/src/bytes_codec.rs
+pub struct BytesCodec {
+    state: DecodeState,
+    raw: bool,
+}
+
+impl Decoder for BytesCodec {
+    type Item = BytesMut;
+    type Error = std::io::Error;
+
+    fn decode(&mut self, buf: &mut BytesMut) -> Result<Option<BytesMut>, Self::Error> {
+        if self.raw {
+            // 原始模式：直接返回数据
+            if buf.is_empty() {
+                Ok(None)
+            } else {
+                Ok(Some(buf.split()))
+            }
+        } else {
+            // 标准模式：4 字节长度前缀 + 数据
+            match self.state {
+                DecodeState::Head => {
+                    if buf.len() < 4 {
+                        return Ok(None);
+                    }
+                    let len = u32::from_le_bytes([buf[0], buf[1], buf[2], buf[3]]) as usize;
+                    buf.advance(4);
+                    self.state = DecodeState::Data(len);
+                    self.decode(buf)
+                }
+                DecodeState::Data(len) => {
+                    if buf.len() < len {
+                        return Ok(None);
+                    }
+                    let data = buf.split_to(len);
+                    self.state = DecodeState::Head;
+                    Ok(Some(data))
+                }
+            }
+        }
+    }
+}
+```
+
+### 加密模式
+
+当启用加密时，消息结构为：
+
+```
+┌─────────────┬─────────────┬─────────────────────────┐
+│  Length(4)  │  Nonce(8)   │  Encrypted Data(N)      │
+└─────────────┴─────────────┴─────────────────────────┘
+```