refactor: flatten dto entity and mapper packages

src/main/java/com/label/dto/TaskResponse.java

@@ -0,0 +1,38 @@
+package com.label.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.Builder;
+import lombok.Data;
+
+import java.time.LocalDateTime;
+
+/**
+ * 任务接口统一响应体（任务池、我的任务、任务详情均复用）。
+ */
+@Data
+@Builder
+@Schema(description = "标注任务响应")
+public class TaskResponse {
+    @Schema(description = "任务主键")
+    private Long id;
+    @Schema(description = "关联资料 ID")
+    private Long sourceId;
+    /** 任务类型（对应 taskType 字段）：EXTRACTION / QA_GENERATION */
+    @Schema(description = "任务类型", example = "EXTRACTION")
+    private String taskType;
+    @Schema(description = "任务状态", example = "UNCLAIMED")
+    private String status;
+    @Schema(description = "领取人用户 ID")
+    private Long claimedBy;
+    @Schema(description = "领取时间")
+    private LocalDateTime claimedAt;
+    @Schema(description = "提交时间")
+    private LocalDateTime submittedAt;
+    @Schema(description = "完成时间")
+    private LocalDateTime completedAt;
+    /** 驳回原因（REJECTED 状态时非空） */
+    @Schema(description = "驳回原因")
+    private String rejectReason;
+    @Schema(description = "创建时间")
+    private LocalDateTime createdAt;
+}