feat: implement payment order system (create-order, mock-confirm, get-quota)

src/models.rs

@@ -327,3 +327,31 @@ impl AppState {
         })
     }
 }
+
+// ===== 支付系统 =====
+
+/// 创建订单请求体
+#[derive(Debug, Deserialize)]
+pub struct CreateOrderRequest {
+    pub package_type: String,
+}
+
+/// 模拟确认支付请求体
+#[derive(Debug, Deserialize)]
+pub struct MockConfirmRequest {
+    pub order_id: String,
+}
+
+/// payment_orders 表行结构
+#[derive(Debug, Serialize, FromRow)]
+pub struct PaymentOrder {
+    pub id: i32,
+    pub user_id: i32,
+    pub order_no: String,
+    pub package_type: String,
+    pub amount: i32,
+    pub status: String,
+    pub paid_at: Option<chrono::DateTime<chrono::Utc>>,
+    pub expires_at: Option<chrono::DateTime<chrono::Utc>>,
+    pub created_at: chrono::DateTime<chrono::Utc>,
+}