feat: add export validation results to Excel feature

Add export functionality to CleanerPage that allows users to export
the currently displayed validation results to an Excel file.

- Add ExportResultItem and ExportResultResponse types
- Create ResultExporter service using ExcelJS
- Register cleaner:exportResults IPC handler
- Add exportResults method to preload API
- Connect export button in CleanerPage to export handler

Export features:
- Exports filtered results (respecting manager/visibility filters)
- Includes selection status column
- Saves to app data directory/exports/校验结果.xlsx

Co-Authored-By: Claude (glm-5) <noreply@anthropic.com>

src/main/services/excel/result-exporter.ts

@@ -0,0 +1,113 @@
+import ExcelJS from 'exceljs'
+import path from 'path'
+import { app } from 'electron'
+import fs from 'fs'
+import { createLogger } from '../logger'
+import type { ExportResultItem, ExportResultResponse } from '../../types/cleaner.types'
+
+const log = createLogger('ResultExporter')
+
+/**
+ * Excel exporter for validation results
+ * Exports filtered validation results to Excel file
+ */
+export class ResultExporter {
+  private readonly exportDir: string
+  private readonly fileName: string = '校验结果.xlsx'
+
+  constructor() {
+    // Export to app directory/exports
+    this.exportDir = path.join(app.getPath('userData'), 'exports')
+    this.ensureExportDir()
+  }
+
+  /**
+   * Ensure export directory exists
+   */
+  private ensureExportDir(): void {
+    if (!fs.existsSync(this.exportDir)) {
+      fs.mkdirSync(this.exportDir, { recursive: true })
+      log.info('Created export directory', { path: this.exportDir })
+    }
+  }
+
+  /**
+   * Export validation results to Excel
+   * @param items - Validation result items to export
+   * @returns Export result with file path or error
+   */
+  async exportValidationResults(items: ExportResultItem[]): Promise<ExportResultResponse> {
+    try {
+      const filePath = path.join(this.exportDir, this.fileName)
+      log.info('Exporting validation results', { count: items.length, path: filePath })
+
+      const workbook = new ExcelJS.Workbook()
+      const worksheet = workbook.addWorksheet('校验结果')
+
+      // Define columns
+      worksheet.columns = [
+        { header: '材料名称', key: 'materialName', width: 30 },
+        { header: '材料代码', key: 'materialCode', width: 20 },
+        { header: '规格', key: 'specification', width: 25 },
+        { header: '型号', key: 'model', width: 20 },
+        { header: '负责人', key: 'managerName', width: 15 },
+        { header: '勾选状态', key: 'isSelectedText', width: 12 },
+        { header: '是否标记删除', key: 'isMarkedForDeletionText', width: 14 }
+      ]
+
+      // Style header row
+      const headerRow = worksheet.getRow(1)
+      headerRow.font = { bold: true }
+      headerRow.fill = {
+        type: 'pattern',
+        pattern: 'solid',
+        fgColor: { argb: 'FFE0E0E0' }
+      }
+      headerRow.alignment = { horizontal: 'center' }
+
+      // Add data rows
+      for (const item of items) {
+        worksheet.addRow({
+          materialName: item.materialName || '',
+          materialCode: item.materialCode || '',
+          specification: item.specification || '',
+          model: item.model || '',
+          managerName: item.managerName || '',
+          isSelectedText: item.isSelected ? '是' : '否',
+          isMarkedForDeletionText: item.isMarkedForDeletion ? '是' : '否'
+        })
+      }
+
+      // Style data rows
+      for (let i = 2; i <= worksheet.rowCount; i++) {
+        const row = worksheet.getRow(i)
+        row.alignment = { vertical: 'middle' }
+
+        // Highlight selected items
+        if (items[i - 2]?.isSelected) {
+          row.fill = {
+            type: 'pattern',
+            pattern: 'solid',
+            fgColor: { argb: 'FFE6F3FF' }
+          }
+        }
+      }
+
+      // Save file
+      await workbook.xlsx.writeFile(filePath)
+      log.info('Export completed', { path: filePath, rows: items.length })
+
+      return {
+        success: true,
+        filePath
+      }
+    } catch (error) {
+      const errorMessage = error instanceof Error ? error.message : String(error)
+      log.error('Export failed', { error: errorMessage })
+      return {
+        success: false,
+        error: errorMessage
+      }
+    }
+  }
+}