Update: 将子项目从 submodule 转为完整内容

- 移除 GovAI, nomifun-tauri, 算力盒子 的 submodule 引用
- 添加所有子项目的完整源代码
- 保留原始 .git 为 .git.bak 备份

nomifun-tauri/crates/backend/nomifun-db/src/models/user.rs

@@ -0,0 +1,61 @@
+use nomifun_common::TimestampMs;
+use serde::{Deserialize, Serialize};
+
+/// User role enum for RBAC
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[serde(rename_all = "lowercase")]
+pub enum UserRole {
+    #[default]
+    User,
+    Admin,
+}
+
+impl UserRole {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            UserRole::User => "user",
+            UserRole::Admin => "admin",
+        }
+    }
+
+    pub fn from_str(s: &str) -> Self {
+        match s.to_lowercase().as_str() {
+            "admin" => UserRole::Admin,
+            _ => UserRole::User,
+        }
+    }
+
+    pub fn is_admin(&self) -> bool {
+        matches!(self, UserRole::Admin)
+    }
+}
+
+/// Row mapping for the `users` table.
+///
+/// All fields match the SQLite column names and types exactly.
+/// Optional fields correspond to nullable columns.
+#[derive(Debug, Clone, Serialize, Deserialize, sqlx::FromRow)]
+pub struct User {
+    pub id: String,
+    pub username: String,
+    pub email: Option<String>,
+    pub password_hash: String,
+    pub role: String,  // 'admin' or 'user'
+    pub avatar_path: Option<String>,
+    pub jwt_secret: Option<String>,
+    pub created_at: TimestampMs,
+    pub updated_at: TimestampMs,
+    pub last_login: Option<TimestampMs>,
+}
+
+impl User {
+    /// Get the parsed role
+    pub fn role(&self) -> UserRole {
+        UserRole::from_str(&self.role)
+    }
+
+    /// Check if user is admin
+    pub fn is_admin(&self) -> bool {
+        self.role().is_admin()
+    }
+}