fix: 批量添加工工作组调试回显 + 完整验证写入

- 后端 /users/batch 返回每条成功记录的 groups_written/groups_expected/group_ids_out；失败记录返回 group_ids_seen/count
- 前端 submitBatch：console.log 打印发送 payload 和响应；弹窗汇总工作组实际/期望写入数；任何异常的行都显示后端实际解析出的 group_ids_out，失败行同时显示后端收到的 group_ids_seen
- 本地模拟后端 sql.js 写入 user_groups 100% 正确（场景A/B测试均 changes=1，聚合查询正确），此提交部署后通过控制台和弹窗即可精确定位问题在哪一跳（前端发送 vs 后端解析 vs 数据库写入）
- npm run build 通过

client/src/pages/admin/Users.tsx

@@ -349,18 +349,29 @@ export default function Users() {
         volunteer_no: r.volunteer_no || null,
         group_ids: r.group_ids,
       }));
+      console.log('[DEBUG] batch payload items (first 3):', JSON.stringify(items.slice(0, 3), null, 2));
       const result = await usersApi.batch(items);
+      console.log('[DEBUG] batch response:', result);
       setBatchErrors('');
-      const msg = `批量添加完成：共 ${result.total} 条，成功 ${result.success} 条，失败 ${result.failed} 条`;
+      const totalActualWritten = result.results.filter(r => r.ok).reduce((sum: number, r: any) => sum + (r?.groups_written ?? 0), 0);
+      const totalExpectedWritten = result.results.filter(r => r.ok).reduce((sum: number, r: any) => sum + (r?.groups_expected ?? 0), 0);
+      const msg = `批量添加完成：共 ${result.total} 条，成功 ${result.success} 条，失败 ${result.failed} 条
+工作组写入：实际 ${totalActualWritten} 条，期望 ${totalExpectedWritten} 条`;
       if (result.failed === 0) {
-        alert(msg);
+        const mis = result.results.filter((r: any) => r.ok && (r?.groups_written ?? 0) !== (r?.groups_expected ?? 0));
+        if (mis.length === 0) {
+          alert(msg);
+        } else {
+          const lines = mis.slice(0, 20).map((r: any) => `第${r.idx + 1}行 ${r.item.name}：期望 ${r.groups_expected} 组，实际写入 ${r.groups_written} 组（后端解析 group_ids_out=${JSON.stringify(r.group_ids_out ?? [])}）`).join('\n');
+          alert(`${msg}\n\n工作组未全部写入（前20）：\n${lines}`);
+        }
         setBatchOpen(false);
         setBatchText('');
         load();
       } else {
         const failLines = result.results
           .filter((r) => !r.ok)
-          .map((r) => `第${r.idx + 1}行 [${r.item.class} ${r.item.name}]：${r.error}`)
+          .map((r: any) => `第${r.idx + 1}行 [${r.item.class} ${r.item.name}]：${r.error}（后端接收 group_ids_count=${r.group_ids_count ?? 'N/A'}，内容=${JSON.stringify(r.group_ids_seen ?? null)}）`)
           .join('\n');
         alert(`${msg}\n\n失败明细：\n${failLines}`);
         load();

server/src/routes/users.ts

@@ -214,17 +214,36 @@ router.post('/batch', authMiddleware, (req: AuthRequest, res: Response) => {
       try {
         const info = insertUser.run(cls, name, volunteer_no, firstGroup);
         const userId = Number(info.lastInsertRowid);
+        let ugCount = 0;
         if (groups.length > 0) {
           const insertUG = db.prepareCompat('INSERT OR IGNORE INTO user_groups (user_id, group_id) VALUES (?,?)');
-          for (const gid of groups) insertUG.run(userId, gid);
+          for (const gid of groups) {
+            const ugInfo = insertUG.run(userId, gid);
+            if ((ugInfo?.changes ?? 0) > 0) ugCount++;
+          }
         }
         success++;
-        results.push({ idx: i, ok: true, id: userId, item: raw });
+        results.push({
+          idx: i,
+          ok: true,
+          id: userId,
+          item: raw,
+          groups_written: ugCount,
+          groups_expected: groups.length,
+          group_ids_out: groups.slice(),
+        } as any);
       } catch (e: any) {
         failed++;
         let err = e?.message || '添加失败';
         if (String(err).includes('UNIQUE')) err = '该班级下已存在同名部员';
-        results.push({ idx: i, ok: false, error: err, item: raw });
+        results.push({
+          idx: i,
+          ok: false,
+          error: err,
+          item: raw,
+          group_ids_seen: Array.isArray(raw.group_ids) ? raw.group_ids : null,
+          group_ids_count: Array.isArray(raw.group_ids) ? raw.group_ids.length : 0,
+        } as any);
       }
     }
     db.execCompat('COMMIT');