style(export): 四小时导出采用简洁矩阵样式，匹配参考表格

- 新增 cleanMatrix 样式：仅上下横线边框、无填充底色、全列居中+自动换行
- 部员列 16pt、义工号/合计列 14pt 加粗、活动列 12pt 宋体
- 新增标题行支持：首列左对齐大标题，末列居中日戳
- 四小时导出移除班级/工作组列，列结构对齐参考表
- 表头行高与数据行高均按内容行数自适应
- 自动筛选范围修正为从表头行开始

client/src/pages/admin/FourHourExport.tsx

@@ -203,9 +203,7 @@ export default function FourHourExport() {
     const data = users.map((u: any) => {
       const row: any = {
         '部员': u.name,
-        '班级': u.class || '-',
         '义工号': u.volunteer_no || '-',
-        '工作组': u.group_name || '-',
       };
       for (const a of activities) {
         const h = Number(u[String(a.id)] || 0);
@@ -224,10 +222,13 @@ export default function FourHourExport() {
     sheets.push({
       name: '活动矩阵总表（四小时核销）',
       data,
-      hint: firstColTitle ? {
+      hint: {
-        matrixColStart: firstColTitle,
+        style: 'cleanMatrix',
+        title: '宣传部义工时长记录系统 · 四小时导出核销',
+        subtitle: utc8DateStamp(),
+        matrixColStart: firstColTitle || undefined,
         matrixColEnd: '本次核销合计(h)',
-      } : undefined,
+      },
     });
     exportToExcel(sheets, `义工时长-四小时导出-活动矩阵总表-${utc8DateStamp()}.xlsx`);
   };

client/src/utils/export.ts

@@ -96,19 +96,39 @@ export function exportToExcel(
       matrixColEnd?: string;
       /** row index (0-based in data array) of header */
       headerRow?: number;
+      /** cleanMatrix: 仅上下横线、无填充、全居中换行 */
+      style?: 'default' | 'cleanMatrix';
+      /** 标题行文本（首列），提供时会自动在数据前插入标题行 */
+      title?: string;
+      /** 标题行右侧副文本（末列），如日期 */
+      subtitle?: string;
     };
   }>,
   filename: string
 ) {
   const wb = XLSX.utils.book_new();
   for (const s of sheets) {
-    const ws = XLSX.utils.json_to_sheet(s.data || []);
+    const isClean = s.hint?.style === 'cleanMatrix';
+    const hasTitle = !!s.hint?.title;
+    let sheetData = s.data || [];
+    if (hasTitle && sheetData.length > 0) {
+      const keys = Object.keys(sheetData[0]);
+      const titleRow: any = {};
+      keys.forEach((k, i) => {
+        if (i === 0) titleRow[k] = s.hint!.title || '';
+        else if (i === keys.length - 1) titleRow[k] = s.hint!.subtitle || '';
+        else titleRow[k] = '';
+      });
+      sheetData = [titleRow, ...sheetData];
+    }
+    const ws = XLSX.utils.json_to_sheet(sheetData);
     const rangeRef = ws['!ref'] || 'A1';
     const range = XLSX.utils.decode_range(rangeRef);
+    const headerR = s.hint?.headerRow ?? (hasTitle ? range.s.r + 1 : range.s.r);
     const cols: string[] = [];
     const headers: string[] = [];
     for (let c = range.s.c; c <= range.e.c; c++) {
-      const addr = XLSX.utils.encode_cell({ r: range.s.r, c });
+      const addr = XLSX.utils.encode_cell({ r: headerR, c });
       const cell = ws[addr];
       const headerName = cell ? String(cell.v ?? '') : '';
       headers.push(headerName);
@@ -117,7 +137,7 @@ export function exportToExcel(
     ws['!cols'] = headers.map((name, idx) => {
       const colLetter = cols[idx];
       let max = Math.max(8, String(name ?? '').length + 2);
-      const startRow = s.hint?.numericStartRow ?? (range.s.r + 1);
+      const startRow = s.hint?.numericStartRow ?? (headerR + 1);
       for (let r = startRow; r <= Math.min(range.e.r, startRow + 1999); r++) {
         const a = XLSX.utils.encode_cell({ r, c: range.s.c + idx });
         const v = ws[a];
@@ -141,10 +161,19 @@ export function exportToExcel(
       // eslint-disable-next-line @typescript-eslint/no-unused-vars
       void colLetter;
     });
-    const headerR = s.hint?.headerRow ?? range.s.r;
     // 1. Header 样式
     for (let c = range.s.c; c <= range.e.c; c++) {
       const addr = XLSX.utils.encode_cell({ r: headerR, c });
+      if (isClean) {
+        applyCellStyle(ws, addr, {
+          bold: true,
+          align: 'center',
+          fontSize: 12,
+          wrap: true,
+          top: true,
+          bottom: true,
+        });
+      } else {
         applyCellStyle(ws, addr, {
           bold: true,
           align: 'center',
@@ -155,9 +184,37 @@ export function exportToExcel(
           borderAll: true,
         });
       }
+    }
+    // 标题行样式（首列左对齐大字号加粗，末列居中）
+    if (hasTitle) {
+      for (let c = range.s.c; c <= range.e.c; c++) {
+        const addr = XLSX.utils.encode_cell({ r: range.s.r, c });
+        if (!ws[addr]) continue;
+        if (c === range.s.c) {
+          applyCellStyle(ws, addr, {
+            bold: true,
+            align: 'left',
+            fontSize: 16,
+            wrap: false,
+          });
+        } else if (c === range.e.c) {
+          applyCellStyle(ws, addr, {
+            align: 'center',
+            fontSize: 12,
+            wrap: false,
+          });
+        }
+      }
+      if (!ws['!rows']) ws['!rows'] = [];
+      ws['!rows'][range.s.r] = { hpt: 28 };
+    }
     // 首行冻结（表头行下一行）
     ws['!freeze'] = { xSplit: 0, ySplit: Math.min(headerR + 1, range.e.r + 1) };
-    ws['!autofilter'] = { ref: XLSX.utils.encode_range(range) };
+    const filterRange = XLSX.utils.encode_range({
+      s: { r: headerR, c: range.s.c },
+      e: { r: range.e.r, c: range.e.c },
+    });
+    ws['!autofilter'] = { ref: filterRange };
     // 2. body 样式 + 数字列 + 居中等 + 交替底色
     const numericColIdx = new Set<number>();
     for (let c = range.s.c; c <= range.e.c; c++) {
@@ -200,8 +257,11 @@ export function exportToExcel(
       }
     }
     const dataStartR = headerR + 1;
+    const firstCol = range.s.c;
+    const lastCol = range.e.c;
+    const volNoColIdx = headers.indexOf('义工号');
     for (let r = dataStartR; r <= range.e.r; r++) {
-      const altFill = ((r - dataStartR) % 2 === 1) ? ALT_ROW : undefined;
+      const altFill = isClean ? undefined : (((r - dataStartR) % 2 === 1) ? ALT_ROW : undefined);
       for (let c = range.s.c; c <= range.e.c; c++) {
         const addr = XLSX.utils.encode_cell({ r, c });
         if (!ws[addr]) {
@@ -212,6 +272,19 @@ export function exportToExcel(
         const isCenter = centerColIdx.has(c);
         const inMatrix = (matrixCS >= 0 && matrixCE >= 0) && (c >= matrixCS && c <= matrixCE);
         const isTotalCol = (headers[c - range.s.c] === '总时长');
+        if (isClean) {
+          const isVolNo = c - range.s.c === volNoColIdx;
+          const isFirst = c === firstCol;
+          const isLast = c === lastCol;
+          applyCellStyle(ws, addr, {
+            align: 'center',
+            wrap: true,
+            top: true,
+            bottom: true,
+            bold: isVolNo || isLast,
+            fontSize: isFirst ? 16 : (isVolNo || isLast ? 14 : 12),
+          });
+        } else {
           applyCellStyle(ws, addr, {
             align: (inMatrix || isCenter || isNum) ? 'center' : 'left',
             numFmt: (isNum || inMatrix) ? '0.0' : undefined,
@@ -231,6 +304,7 @@ export function exportToExcel(
             };
           }
         }
+      }
       // 行高：根据每个单元格换行估算（备注行或矩阵有备注行高放大）
       let lines = 1;
       for (let c = range.s.c; c <= range.e.c; c++) {