fix(ops): 取消工单接口改用 @RequestBody 接收 JSON 参数

前端以 JSON body 传参，@RequestParam 无法读取导致 400 "请求参数缺失"。
新增 OpsOrderCancelReqDTO，Controller 改为 @RequestBody 风格，
与 create/assign/complete 等接口保持一致。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

viewsh-module-ops/viewsh-module-ops-biz/src/main/java/com/viewsh/module/ops/dal/dataobject/dto/OpsOrderCancelReqDTO.java

@@ -0,0 +1,25 @@
+package com.viewsh.module.ops.dal.dataobject.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import lombok.Data;
+
+/**
+ * 工单取消请求 DTO
+ *
+ * @author lzh
+ */
+@Schema(description = "管理后台 - 工单取消 Request DTO")
+@Data
+public class OpsOrderCancelReqDTO {
+
+    @Schema(description = "工单ID", requiredMode = Schema.RequiredMode.REQUIRED, example = "1001")
+    @NotNull(message = "工单ID不能为空")
+    private Long id;
+
+    @Schema(description = "取消原因", requiredMode = Schema.RequiredMode.REQUIRED, example = "客户要求取消")
+    @NotBlank(message = "取消原因不能为空")
+    private String reason;
+
+}