refactor: 后端核心模块功能增强与代码优化

- 完善 User/Product/Order 实体字段和关联关系
- 更新 DTO 适配新增字段
- 增强 Service 层业务逻辑和 Repository 查询方法
- 优化控制器接口，完善管理后台 API
- 新增请求监控过滤器和指标服务

src/main/java/com/org/flashsalesystem/entity/Order.java

@@ -26,6 +26,12 @@ public class Order {
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
 
+    @Column(name = "order_no", nullable = false, unique = true, length = 64)
+    private String orderNo;
+
+    @Column(name = "group_no", length = 64)
+    private String groupNo;
+
     @NotNull(message = "用户ID不能为空")
     @Column(name = "user_id", nullable = false)
     private Long userId;
@@ -58,6 +64,30 @@ public class Order {
     @Column(name = "created_at", nullable = false, updatable = false)
     private LocalDateTime createdAt;
 
+    @Column(name = "receiver_name", length = 100)
+    private String receiverName;
+
+    @Column(name = "receiver_phone", length = 20)
+    private String receiverPhone;
+
+    @Column(name = "receiver_address", length = 255)
+    private String receiverAddress;
+
+    @Column(name = "remark", length = 255)
+    private String remark;
+
+    @Column(name = "payment_method", length = 50)
+    private String paymentMethod;
+
+    @Column(name = "paid_at")
+    private LocalDateTime paidAt;
+
+    @Column(name = "shipped_at")
+    private LocalDateTime shippedAt;
+
+    @Column(name = "completed_at")
+    private LocalDateTime completedAt;
+
     @Column(name = "updated_at")
     private LocalDateTime updatedAt;
 
@@ -73,6 +103,9 @@ public class Order {
     protected void onCreate() {
         createdAt = LocalDateTime.now();
         updatedAt = LocalDateTime.now();
+        if (orderNo == null || orderNo.trim().isEmpty()) {
+            orderNo = "FS" + System.currentTimeMillis();
+        }
     }
 
     @PreUpdate

src/main/java/com/org/flashsalesystem/entity/Product.java

@@ -39,6 +39,9 @@ public class Product {
     @Column(nullable = false, precision = 10, scale = 2)
     private BigDecimal price;
 
+    @Column(length = 100)
+    private String category;
+
     @Min(value = 0, message = "库存不能为负数")
     @Column(nullable = false)
     private Integer stock = 0;
@@ -60,6 +63,9 @@ public class Product {
 
     @PrePersist
     protected void onCreate() {
+        if (category == null || category.trim().isEmpty()) {
+            category = "默认分类";
+        }
         createdAt = LocalDateTime.now();
         updatedAt = LocalDateTime.now();
     }

src/main/java/com/org/flashsalesystem/entity/User.java

@@ -43,9 +43,15 @@ public class User {
     @Column(length = 20)
     private String phone;
 
+    @Column(length = 500)
+    private String avatar;
+
     @Column(name = "status", nullable = false)
     private Integer status = 1; // 1-正常, 0-禁用
 
+    @Column(name = "role", nullable = false, length = 20)
+    private String role = "USER";
+
     @Column(name = "last_login")
     private LocalDateTime lastLogin;
 
@@ -57,6 +63,9 @@ public class User {
 
     @PrePersist
     protected void onCreate() {
+        if (role == null || role.trim().isEmpty()) {
+            role = "USER";
+        }
         createdAt = LocalDateTime.now();
         updatedAt = LocalDateTime.now();
     }