feat(dict): 票09 步3 DictQueryService 加 listTree/listChildren 树形读

- listTree(groupCode): 复用扁平启用列表内存组两级树, 一级为根带 children(仅启用子项), 不新建缓存key (Q4)
- listChildren(groupCode, parentCode): 取一级项直接启用子项, 父不存在返空
- DictItemDTO 加 children (仅 listTree 填充); getItem/listEnabledItems 扁平接口不变, 现存消费方零改动
- 测试助手 newChildItem; 新增2测试 listTree_twoLevel/listChildren_byParentCode; 50 全绿 (+2)

crm-dict/src/main/java/com/crm/dict/domain/dto/DictItemDTO.java

@@ -48,6 +48,9 @@ public class DictItemDTO extends BaseDTO {
     @Schema(description = "是否有效可选（分组与项均启用）")
     private Boolean effectiveSelectable;
 
+    @Schema(description = "二级子项（仅 listTree 返回时填充；二级项自身为空/null）")
+    private java.util.List<DictItemDTO> children;
+
     /**
      * Entity → DTO（出参转换，Service 层调用）
      */

crm-dict/src/main/java/com/crm/dict/service/DictQueryService.java

@@ -25,6 +25,19 @@ public interface DictQueryService {
      */
     List<DictItemDTO> listEnabledItems(String groupCode);
 
+    /**
+     * 分组启用字典项两级树（业务树形选择器渲染用）：仅返回分组与项均启用的项，
+     * 顶层（parentId=null）作为树根带 children（也只含启用子项）；父启用但无启用子项时 children 为空列表。
+     * 分组不存在/停用时返回空列表。复用扁平启用列表内存组树（Q4）。
+     */
+    List<DictItemDTO> listTree(String groupCode);
+
+    /**
+     * 某一级项下的启用二级子项列表（级联选择器选完一级再拉二级用）；
+     * 分组/父项不存在或停用时返回空列表，按 sort_no 排序（空排最后）。
+     */
+    List<DictItemDTO> listChildren(String groupCode, String parentCode);
+
     /**
      * 分组当前默认项：联查 group.status，分组停用（休眠）或未设默认时返回 null
      */

crm-dict/src/main/java/com/crm/dict/service/impl/DictQueryServiceImpl.java

@@ -97,6 +97,44 @@ public class DictQueryServiceImpl implements DictQueryService {
         return items.stream().map(DictItemDTO::fromEntity).toList();
     }
 
+    @Override
+    public List<DictItemDTO> listTree(String groupCode) {
+        // 复用已缓存的扁平启用列表，内存组两级树（不新建缓存 key，Q4）
+        List<DictItemDTO> flat = listEnabledItems(groupCode);
+        if (flat.isEmpty()) {
+            return List.of();
+        }
+        List<DictItemDTO> roots = new java.util.ArrayList<>();
+        java.util.Map<Long, List<DictItemDTO>> childrenByParent = new java.util.HashMap<>();
+        for (DictItemDTO dto : flat) {
+            if (dto.getParentId() == null) {
+                roots.add(dto);
+            } else {
+                childrenByParent.computeIfAbsent(dto.getParentId(), k -> new java.util.ArrayList<>()).add(dto);
+            }
+        }
+        for (DictItemDTO root : roots) {
+            root.setChildren(childrenByParent.getOrDefault(root.getId(), List.of()));
+        }
+        return roots;
+    }
+
+    @Override
+    public List<DictItemDTO> listChildren(String groupCode, String parentCode) {
+        // 启用且父启用才可选：复用启用列表，取 parentCode 对应一级项的直接子项
+        List<DictItemDTO> flat = listEnabledItems(groupCode);
+        if (flat.isEmpty()) {
+            return List.of();
+        }
+        DictItemDTO parent = flat.stream()
+                .filter(d -> d.getParentId() == null && parentCode.equals(d.getCode()))
+                .findFirst().orElse(null);
+        if (parent == null) {
+            return List.of();
+        }
+        return flat.stream().filter(d -> parent.getId().equals(d.getParentId())).toList();
+    }
+
     @Override
     public DictItem getDefaultItem(String groupCode) {
         String key = "defaultItem:" + groupCode;

crm-dict/src/test/java/com/crm/dict/AbstractDictH2Test.java

@@ -166,6 +166,14 @@ public abstract class AbstractDictH2Test {
         return i;
     }
 
+    /** 新建二级子项（parentId 指向同组一级项） */
+    protected DictItem newChildItem(Long groupId, Long parentId, String code, String value) {
+        DictItem i = newItem(groupId, code, value);
+        i.setParentId(parentId);
+        dictItemMapper.updateById(i);
+        return i;
+    }
+
     /** 断言抛业务异常且错误码匹配 */
     protected void assertDictError(org.assertj.core.api.ThrowableAssert.ThrowingCallable callable, int expectedCode) {
         assertThatThrownBy(callable)

crm-dict/src/test/java/com/crm/dict/service/impl/DictQueryServiceTest.java

@@ -129,4 +129,36 @@ class DictQueryServiceTest extends AbstractDictH2Test {
         Thread.sleep(2200);
         assertThat(dictQueryService.getItem("g", "late_item")).isNotNull();
     }
+
+    @Test
+    @DisplayName("listTree：一级为根带 children，仅含启用项，分组停用返空")
+    void listTree_twoLevel() {
+        DictGroup g = newGroup("industry", "所属行业");
+        DictItem gov = newItem(g.getId(), "gov", "gov");
+        DictItem edu = newItem(g.getId(), "edu", "edu");
+        newChildItem(g.getId(), gov.getId(), "gov_ncpol", "gov_ncpol");
+        newChildItem(g.getId(), gov.getId(), "gov_emg", "gov_emg");
+        // edu 无启用子项
+
+        List<DictItemDTO> tree = dictQueryService.listTree("industry");
+        assertThat(tree).extracting(DictItemDTO::getCode).containsExactlyInAnyOrder("gov", "edu");
+        DictItemDTO govNode = tree.stream().filter(t -> "gov".equals(t.getCode())).findFirst().orElseThrow();
+        assertThat(govNode.getChildren()).extracting(DictItemDTO::getCode)
+                .containsExactlyInAnyOrder("gov_ncpol", "gov_emg");
+        DictItemDTO eduNode = tree.stream().filter(t -> "edu".equals(t.getCode())).findFirst().orElseThrow();
+        assertThat(eduNode.getChildren()).isEmpty();
+    }
+
+    @Test
+    @DisplayName("listChildren：取一级项直接启用子项；父不存在返空")
+    void listChildren_byParentCode() {
+        DictGroup g = newGroup("industry", "所属行业");
+        DictItem gov = newItem(g.getId(), "gov", "gov");
+        newChildItem(g.getId(), gov.getId(), "gov_ncpol", "gov_ncpol");
+        newChildItem(g.getId(), gov.getId(), "gov_emg", "gov_emg");
+
+        assertThat(dictQueryService.listChildren("industry", "gov"))
+                .extracting(DictItemDTO::getCode).containsExactlyInAnyOrder("gov_ncpol", "gov_emg");
+        assertThat(dictQueryService.listChildren("industry", "not_exist")).isEmpty();
+    }
 }