更新账户更新请求DTO，添加用户类型、用户名和积分余额字段，并在AccountService中实现相应的验证和更新逻辑，确保用户名唯一性和积分余额的正确处理。

src/main/java/com/gameplatform/server/model/dto/account/AccountUpdateRequest.java

@@ -2,15 +2,36 @@ package com.gameplatform.server.model.dto.account;
 
 import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.validation.constraints.Pattern;
+import jakarta.validation.constraints.Size;
 
 @Schema(description = "账户更新请求")
 public class AccountUpdateRequest {
+    @Schema(description = "用户类型", example = "AGENT", allowableValues = {"ADMIN", "AGENT"})
+    @Pattern(regexp = "^(ADMIN|AGENT)$", message = "userType 只能是 ADMIN 或 AGENT")
+    private String userType;
+
+    @Schema(description = "用户名", example = "newuser")
+    @Size(min = 3, max = 64, message = "用户名长度必须在3-64字符之间")
+    @Pattern(regexp = "^[a-zA-Z0-9_]+$", message = "用户名只能包含字母、数字、下划线")
+    private String username;
+
     @Schema(description = "账户状态", example = "ENABLED", allowableValues = {"ENABLED", "DISABLED"})
     @Pattern(regexp = "^(ENABLED|DISABLED)$", message = "status 只能是 ENABLED 或 DISABLED")
     private String status;
 
+    @Schema(description = "积分余额（仅AGENT类型有效）", example = "100")
+    private Long pointsBalance;
+
+    public String getUserType() { return userType; }
+    public void setUserType(String userType) { this.userType = userType; }
+
+    public String getUsername() { return username; }
+    public void setUsername(String username) { this.username = username; }
 
     public String getStatus() { return status; }
     public void setStatus(String status) { this.status = status; }
+
+    public Long getPointsBalance() { return pointsBalance; }
+    public void setPointsBalance(Long pointsBalance) { this.pointsBalance = pointsBalance; }
 }