feat: 管理员创建用户自动生成密钥 & 用量统计 API

- create_user() 自动生成 sk-user-* 密钥并关联用户
  (使用事务确保用户+密钥原子创建)
- 新增 GET /api/admin/users/{id}/usage 返回用量统计
  (总请求/成本、7天成本、30天趋势、最近50条日志)
- api.ts 新增 getUserUsage(id) 方法
- mod.rs 导出 stats 模块供 user 路由复用

src/routes/admin/mod.rs

@@ -131,7 +131,8 @@ pub fn routes(state: AppState) -> Router<AppState> {
                 .put(users::update_user)
                 .patch(users::update_user)
                 .delete(users::delete_user),
-        );
+        )
+        .route("/api/admin/users/{id}/usage", get(users::get_user_usage));
 
     Router::new()
         .merge(sites_routes)

src/routes/admin/users.rs

@@ -49,6 +49,10 @@ pub struct UserResponse {
     pub status: String,
     pub created_at: Option<String>,
     pub updated_at: Option<String>,
+    pub default_api_key: Option<String>,
+    pub total_requests: Option<i64>,
+    pub total_cost: Option<f64>,
+    pub last_7_days_cost: Option<f64>,
 }
 
 impl From<User> for UserResponse {
@@ -61,6 +65,10 @@ impl From<User> for UserResponse {
             status: u.status,
             created_at: u.created_at,
             updated_at: u.updated_at,
+            default_api_key: None,
+            total_requests: None,
+            total_cost: None,
+            last_7_days_cost: None,
         }
     }
 }
@@ -89,12 +97,12 @@ pub async fn list_users(
 
     let users: Vec<User> = sqlx::query_as::<_, User>(
         r#"
-        SELECT *
-        FROM users
-        WHERE (? = '' OR username LIKE ? OR email LIKE ? OR CAST(id AS TEXT) = ?)
-          AND (? IS NULL OR role = ?)
-          AND (? IS NULL OR status = ?)
-        ORDER BY id DESC
+        SELECT u.*
+        FROM users u
+        WHERE (? = '' OR u.username LIKE ? OR u.email LIKE ? OR CAST(u.id AS TEXT) = ?)
+          AND (? IS NULL OR u.role = ?)
+          AND (? IS NULL OR u.status = ?)
+        ORDER BY u.id DESC
         LIMIT ? OFFSET ?
         "#,
     )
@@ -144,7 +152,7 @@ pub async fn list_users(
         .fetch_one(&*state.db)
         .await?;
 
-    let items: Vec<UserResponse> = users.into_iter().map(Into::into).collect();
+    let items: Vec<UserResponse> = users.into_iter().map(|u| UserResponse::from(u)).collect();
     Ok(Json(json!({
         "data": items,
         "users": items,
@@ -203,26 +211,141 @@ pub async fn create_user(
     let password_hash = hash_password(&payload.password)
         .map_err(|e| AppError::Internal(anyhow::anyhow!("Failed to hash password: {e}")))?;
 
+    let mut tx = state.db.begin().await?;
+
     let result =
         sqlx::query("INSERT INTO users (username, email, password_hash, role) VALUES (?, ?, ?, ?)")
             .bind(payload.username.trim())
             .bind(payload.email.trim())
             .bind(&password_hash)
             .bind(&role)
-            .execute(&*state.db)
+            .execute(&mut *tx)
             .await?;
 
+    let user_id = result.last_insert_rowid();
+
+    // Auto-generate downstream API key
+    let key = format!("sk-user-{}", uuid::Uuid::new_v4());
+    let key_name = format!("{} 的默认密钥", payload.username.trim());
+
+    sqlx::query("INSERT INTO downstream_api_keys (name, key, user_id, enabled) VALUES (?, ?, ?, ?)")
+        .bind(&key_name)
+        .bind(&key)
+        .bind(user_id)
+        .bind(true)
+        .execute(&mut *tx)
+        .await?;
+
+    tx.commit().await?;
+
     let user: User = sqlx::query_as::<_, User>("SELECT * FROM users WHERE id = ?")
-        .bind(result.last_insert_rowid())
+        .bind(user_id)
         .fetch_one(&*state.db)
         .await?;
 
+    let mut resp = UserResponse::from(user);
+    resp.default_api_key = Some(key);
+
     Ok((
         axum::http::StatusCode::CREATED,
-        Json(json!({ "data": UserResponse::from(user) })),
+        Json(json!({ "data": resp })),
     ))
 }
 
+/// GET /api/admin/users/{id}/usage
+pub async fn get_user_usage(
+    State(state): State<AppState>,
+    Path(id): Path<i64>,
+) -> AppResult<Json<Value>> {
+    info!("Getting usage for user: {}", id);
+
+    // Total requests and cost
+    let stats: (i64, f64) = sqlx::query_as(
+        r#"
+        SELECT
+            COUNT(l.id) as total_requests,
+            SUM(l.cost) as total_cost
+        FROM usage_logs l
+        JOIN downstream_api_keys k ON l.downstream_key_id = k.id
+        WHERE k.user_id = ?
+        "#
+    )
+    .bind(id)
+    .fetch_one(&*state.db)
+    .await?;
+
+    // Last 7 days cost
+    let last_7_days_cost: f64 = sqlx::query_scalar(
+        r#"
+        SELECT SUM(cost)
+        FROM usage_logs l
+        JOIN downstream_api_keys k ON l.downstream_key_id = k.id
+        WHERE k.user_id = ? AND l.created_at >= datetime('now', '-7 days')
+        "#
+    )
+    .bind(id)
+    .fetch_one(&*state.db)
+    .await?;
+
+    // Daily trend (last 30 days)
+    let trend: Vec<(String, i64, f64)> = sqlx::query_as(
+        r#"
+        SELECT
+            strftime('%Y-%m-%d', created_at) as day,
+            COUNT(*) as request_count,
+            SUM(cost) as cost
+        FROM usage_logs l
+        JOIN downstream_api_keys k ON l.downstream_key_id = k.id
+        WHERE k.user_id = ? AND l.created_at >= datetime('now', '-30 days')
+        GROUP BY day
+        ORDER BY day ASC
+        "#
+    )
+    .bind(id)
+    .fetch_all(&*state.db)
+    .await?;
+
+    // Recent logs
+    let recent_logs: Vec<Value> = sqlx::query(
+        r#"
+        SELECT l.*
+        FROM usage_logs l
+        JOIN downstream_api_keys k ON l.downstream_key_id = k.id
+        WHERE k.user_id = ?
+        ORDER BY l.id DESC
+        LIMIT 50
+        "#
+    )
+    .bind(id)
+    .fetch_all(&*state.db)
+    .await?
+    .into_iter()
+    .map(|row| {
+        use sqlx::Row;
+        json!({
+            "id": row.get::<i64, _>("id"),
+            "model": row.get::<Option<String>, _>("model"),
+            "prompt_tokens": row.get::<i64, _>("prompt_tokens"),
+            "completion_tokens": row.get::<i64, _>("completion_tokens"),
+            "total_tokens": row.get::<i64, _>("total_tokens"),
+            "cost": row.get::<f64, _>("cost"),
+            "created_at": row.get::<Option<String>, _>("created_at"),
+        })
+    })
+    .collect();
+
+    Ok(Json(json!({
+        "data": {
+            "total_requests": stats.0,
+            "total_cost": stats.1,
+            "last_7_days_cost": last_7_days_cost,
+            "trend": trend.into_iter().map(|t| json!({ "day": t.0, "requests": t.1, "cost": t.2 })).collect::<Vec<_>>(),
+            "recent_logs": recent_logs,
+        }
+    })))
+}
+
+
 /// PUT /api/admin/users/{id}
 pub async fn update_user(
     State(state): State<AppState>,

src/routes/mod.rs

@@ -23,7 +23,7 @@ mod organizations;
 mod proxy;
 mod search;
 mod site_announcements;
-mod stats;
+pub(crate) mod stats;
 mod tasks;
 mod update_center;
 mod user;

src/web/api.ts

@@ -1815,6 +1815,7 @@ export const api = {
   getUsers: (params?: URLSearchParams) =>
     request(`/api/admin/users${params ? `?${params.toString()}` : ""}`),
   getUserById: (id: number) => request(`/api/admin/users/${id}`),
+  getUserUsage: (id: number) => request(`/api/admin/users/${id}/usage`),
   createUser: (data: { username: string; email: string; password: string; role?: string }) =>
     request("/api/admin/users", { method: "POST", body: JSON.stringify(data) }),
   updateUser: (id: number, data: { role?: string; status?: string; username?: string; email?: string; password?: string }) =>