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/modules/auth.md

@@ -0,0 +1,340 @@
+# Auth 模块文档
+
+## 1. 模块概述
+
+Auth 模块提供用户认证和会话管理功能。
+
+### 1.1 主要功能
+
+- 用户管理
+- 密码哈希 (Argon2)
+- 会话管理
+- 认证中间件
+- 权限控制
+
+### 1.2 文件结构
+
+```
+src/auth/
+├── mod.rs              # 模块导出
+├── user.rs             # 用户管理 (5KB)
+├── session.rs          # 会话管理 (4KB)
+├── password.rs         # 密码哈希 (1KB)
+└── middleware.rs       # 中间件 (4KB)
+```
+
+---
+
+## 2. 核心组件
+
+### 2.1 UserStore (user.rs)
+
+```rust
+pub struct UserStore {
+    db: Pool<Sqlite>,
+}
+
+impl UserStore {
+    /// 创建存储
+    pub async fn new(db: Pool<Sqlite>) -> Result<Self>;
+
+    /// 创建用户
+    pub async fn create_user(&self, user: &CreateUser) -> Result<User>;
+
+    /// 获取用户
+    pub async fn get_user(&self, id: &str) -> Result<Option<User>>;
+
+    /// 按用户名获取
+    pub async fn get_by_username(&self, username: &str) -> Result<Option<User>>;
+
+    /// 更新用户
+    pub async fn update_user(&self, id: &str, update: &UpdateUser) -> Result<()>;
+
+    /// 删除用户
+    pub async fn delete_user(&self, id: &str) -> Result<()>;
+
+    /// 列出用户
+    pub async fn list_users(&self) -> Result<Vec<User>>;
+
+    /// 验证密码
+    pub async fn verify_password(&self, username: &str, password: &str) -> Result<Option<User>>;
+
+    /// 更新密码
+    pub async fn update_password(&self, id: &str, new_password: &str) -> Result<()>;
+
+    /// 检查是否需要初始化
+    pub async fn needs_setup(&self) -> Result<bool>;
+}
+
+pub struct User {
+    pub id: String,
+    pub username: String,
+    pub role: UserRole,
+    pub created_at: DateTime<Utc>,
+}
+
+pub enum UserRole {
+    Admin,
+    User,
+}
+
+pub struct CreateUser {
+    pub username: String,
+    pub password: String,
+    pub role: UserRole,
+}
+```
+
+### 2.2 SessionStore (session.rs)
+
+```rust
+pub struct SessionStore {
+    /// 会话映射
+    sessions: RwLock<HashMap<String, Session>>,
+
+    /// 会话超时
+    timeout: Duration,
+}
+
+impl SessionStore {
+    /// 创建存储
+    pub fn new(timeout: Duration) -> Self;
+
+    /// 创建会话
+    pub fn create_session(&self, user: &User) -> String;
+
+    /// 获取会话
+    pub fn get_session(&self, token: &str) -> Option<Session>;
+
+    /// 删除会话
+    pub fn delete_session(&self, token: &str);
+
+    /// 清理过期会话
+    pub fn cleanup_expired(&self);
+
+    /// 刷新会话
+    pub fn refresh_session(&self, token: &str) -> bool;
+}
+
+pub struct Session {
+    pub token: String,
+    pub user_id: String,
+    pub username: String,
+    pub role: UserRole,
+    pub created_at: Instant,
+    pub last_active: Instant,
+}
+```
+
+### 2.3 密码哈希 (password.rs)
+
+```rust
+/// 哈希密码
+pub fn hash_password(password: &str) -> Result<String> {
+    let salt = SaltString::generate(&mut OsRng);
+    let argon2 = Argon2::default();
+    let hash = argon2
+        .hash_password(password.as_bytes(), &salt)?
+        .to_string();
+    Ok(hash)
+}
+
+/// 验证密码
+pub fn verify_password(password: &str, hash: &str) -> Result<bool> {
+    let parsed_hash = PasswordHash::new(hash)?;
+    Ok(Argon2::default()
+        .verify_password(password.as_bytes(), &parsed_hash)
+        .is_ok())
+}
+```
+
+### 2.4 认证中间件 (middleware.rs)
+
+```rust
+pub async fn auth_middleware(
+    State(state): State<Arc<AppState>>,
+    cookies: Cookies,
+    request: Request,
+    next: Next,
+) -> Response {
+    // 获取 session token
+    let token = cookies
+        .get("session_id")
+        .map(|c| c.value().to_string());
+
+    // 验证会话
+    let session = token
+        .and_then(|t| state.sessions.get_session(&t));
+
+    if let Some(session) = session {
+        // 将用户信息注入请求
+        let mut request = request;
+        request.extensions_mut().insert(session);
+        next.run(request).await
+    } else {
+        StatusCode::UNAUTHORIZED.into_response()
+    }
+}
+
+pub async fn admin_middleware(
+    session: Extension<Session>,
+    request: Request,
+    next: Next,
+) -> Response {
+    if session.role == UserRole::Admin {
+        next.run(request).await
+    } else {
+        StatusCode::FORBIDDEN.into_response()
+    }
+}
+```
+
+---
+
+## 3. API 端点
+
+| 端点 | 方法 | 权限 | 描述 |
+|------|------|------|------|
+| `/api/auth/login` | POST | Public | 登录 |
+| `/api/auth/logout` | POST | User | 登出 |
+| `/api/auth/check` | GET | User | 检查认证 |
+| `/api/auth/password` | POST | User | 修改密码 |
+| `/api/users` | GET | Admin | 列出用户 |
+| `/api/users` | POST | Admin | 创建用户 |
+| `/api/users/:id` | DELETE | Admin | 删除用户 |
+| `/api/setup/init` | POST | Public | 初始化设置 |
+
+### 请求/响应格式
+
+```json
+// POST /api/auth/login
+// Request:
+{
+    "username": "admin",
+    "password": "password123"
+}
+
+// Response:
+{
+    "user": {
+        "id": "uuid",
+        "username": "admin",
+        "role": "admin"
+    }
+}
+
+// GET /api/auth/check
+{
+    "authenticated": true,
+    "user": {
+        "id": "uuid",
+        "username": "admin",
+        "role": "admin"
+    }
+}
+```
+
+---
+
+## 4. 配置
+
+```rust
+#[derive(Serialize, Deserialize)]
+#[typeshare]
+pub struct AuthConfig {
+    /// 会话超时 (秒)
+    pub session_timeout_secs: u64,
+
+    /// 是否启用认证
+    pub enabled: bool,
+}
+
+impl Default for AuthConfig {
+    fn default() -> Self {
+        Self {
+            session_timeout_secs: 86400,  // 24 小时
+            enabled: true,
+        }
+    }
+}
+```
+
+---
+
+## 5. 安全特性
+
+### 5.1 密码存储
+
+- Argon2id 哈希
+- 随机盐值
+- 不可逆
+
+### 5.2 会话安全
+
+- 随机 token (UUID v4)
+- HTTPOnly Cookie
+- 会话超时
+- 自动清理
+
+### 5.3 权限控制
+
+- 两级权限: Admin / User
+- 中间件检查
+- 敏感操作需 Admin
+
+---
+
+## 6. 使用示例
+
+```rust
+// 创建用户
+let user = users.create_user(&CreateUser {
+    username: "admin".to_string(),
+    password: "password123".to_string(),
+    role: UserRole::Admin,
+}).await?;
+
+// 验证密码
+if let Some(user) = users.verify_password("admin", "password123").await? {
+    // 创建会话
+    let token = sessions.create_session(&user);
+
+    // 设置 Cookie
+    cookies.add(Cookie::build("session_id", token)
+        .http_only(true)
+        .path("/")
+        .finish());
+}
+
+// 获取会话
+if let Some(session) = sessions.get_session(&token) {
+    println!("User: {}", session.username);
+}
+```
+
+---
+
+## 7. 错误处理
+
+```rust
+#[derive(Debug, thiserror::Error)]
+pub enum AuthError {
+    #[error("Invalid credentials")]
+    InvalidCredentials,
+
+    #[error("User not found")]
+    UserNotFound,
+
+    #[error("User already exists")]
+    UserExists,
+
+    #[error("Session expired")]
+    SessionExpired,
+
+    #[error("Permission denied")]
+    PermissionDenied,
+
+    #[error("Setup required")]
+    SetupRequired,
+}
+```