feat: 书籍导出添加 exportColumns 补全4个缺失字段 + cover formatter

src/modules/knowledge/views/book/index.vue

@@ -16,7 +16,7 @@
 				tips="请按照模板填写书籍信息，名称为必填项"
 			/>
 			<!-- 导出按钮 -->
-			<cl-export-btn :columns="Table?.columns" filename="书籍列表" />
+			<cl-export-btn :columns="exportColumns" filename="书籍列表" />
 			<!-- 分类筛选 -->
 			<cl-select
 				:options="categoryOptions"
@@ -68,7 +68,7 @@ defineOptions({
 
 import { useCrud, useTable, useUpsert } from '@cool-vue/crud';
 import { useCool } from '/@/cool';
-import { h, reactive, ref } from 'vue';
+import { computed, h, reactive, ref } from 'vue';
 import { useRouter } from 'vue-router';
 import { ElMessage } from 'element-plus';
 import BookCoverEdit from '../../components/book-cover-edit.vue';
@@ -294,6 +294,40 @@ const Table = useTable({
 	]
 });
 
+// 导出列 - 包含表格列 + 额外字段（不在表格展示，导出时可选）
+const exportColumns = computed(() => {
+	const cols: any[] = Table.value?.columns ? [...Table.value.columns] : [];
+	const base = cols.filter((e: any) => !['selection', 'expand', 'index', 'op'].includes(e.type));
+
+	// 为 cover 列添加 formatter（导出时 render 不会被调用，需要 formatter 将数组转为文本）
+	const coverCol = base.find((e: any) => e.prop === 'cover');
+	if (coverCol) {
+		coverCol.formatter = (_row: any, _col: any, value: any) => {
+			if (Array.isArray(value)) {
+				return value.join(', ');
+			}
+			if (typeof value === 'string') {
+				try {
+					const parsed = JSON.parse(value);
+					return Array.isArray(parsed) ? parsed.join(', ') : value;
+				} catch {
+					return value;
+				}
+			}
+			return String(value || '');
+		};
+	}
+
+	base.push(
+		{ label: '内容简介', prop: 'synopsis', minWidth: 300 },
+		{ label: '背景故事', prop: 'backgroundStory', minWidth: 300 },
+		{ label: '标签', prop: 'tags', minWidth: 150 },
+		{ label: '更新时间', prop: 'updateTime', minWidth: 170 }
+	);
+
+	return base;
+});
+
 // cl-upsert 配置 - 新增/编辑表单
 const Upsert = useUpsert({
 	dialog: {