feat: add tenant import console

scripts/api-integration-test.js

@@ -3173,6 +3173,55 @@ async function testTenantContentAssetsAndImports() {
   assert.equal(csvQuestionPreview.job?.validCount, 1, 'CSV question preview should normalize one row');
   assert.equal(csvQuestionPreview.items?.[0]?.normalized?.correctOptionIndices?.[0], 1, 'CSV answer B should map to option index 1');
 
+  const mappedQuestionCsv = [
+    ['旧编号', '题型显示', '自定义题干', '左选项', '右选项', '正确项', '讲解'].join(','),
+    ['integration-import-csv-mapped-001', 'choice', 'CSV字段映射题：导入别名应由谁最终校验？', '前端页面', '后端导入管线', 'B', '字段映射只能进入后端白名单字段。'].join(','),
+  ].join('\n');
+  const mappedCsvPreview = await request('/api/tenant-content/imports/preview/questions', {
+    userId: TENANT_ADMIN_USER_ID,
+    method: 'POST',
+    body: {
+      sourceFormat: 'csv',
+      sourceName: 'questions-mapped.csv',
+      csvText: mappedQuestionCsv,
+      subjectId: ids.subject,
+      categoryId: ids.category,
+      regionId: ids.region,
+      entryId: ids.contentEntry,
+      contentNodeId: ids.contentNodeSchoolTarget,
+      collectionId: ids.questionCollection,
+      fieldMappingOverrides: {
+        legacyId: ['旧编号'],
+        type: ['题型显示'],
+        content: ['自定义题干'],
+        optionA: ['左选项'],
+        optionB: ['右选项'],
+        answer: ['正确项'],
+        explanation: ['讲解'],
+      },
+    },
+  });
+  assert.equal(mappedCsvPreview.job?.errorCount, 0, 'CSV field mapping override preview should have no errors');
+  assert.equal(mappedCsvPreview.items?.[0]?.normalized?.content, 'CSV字段映射题：导入别名应由谁最终校验？', 'field mapping override should map custom stem header');
+  assert.equal(mappedCsvPreview.items?.[0]?.normalized?.correctOptionIndices?.[0], 1, 'field mapping override should map custom answer header');
+
+  const unsafeMappingOverrides = Object.fromEntries([['__proto__', ['旧编号']]]);
+  const deniedMappingTarget = await request('/api/tenant-content/imports/preview/questions', {
+    userId: TENANT_ADMIN_USER_ID,
+    method: 'POST',
+    body: {
+      sourceFormat: 'csv',
+      sourceName: 'questions-bad-mapping.csv',
+      csvText: mappedQuestionCsv,
+      subjectId: ids.subject,
+      categoryId: ids.category,
+      regionId: ids.region,
+      fieldMappingOverrides: unsafeMappingOverrides,
+    },
+    expectStatus: 400,
+  });
+  assert.equal(deniedMappingTarget.code, 'IMPORT_HEADER_UNSAFE', 'field mapping override should reject unsafe target fields');
+
   const csvQuestionImport = await request('/api/tenant-content/imports/questions', {
     userId: TENANT_ADMIN_USER_ID,
     method: 'POST',