feat: 电子签署集成到合同管理和离职流程

- 合同管理：选择电子签署时保存后自动创建ESignRecord并关联合同ID
- 离职管理：工作交接清单「离职文件签署」步骤增加「发起电子签署」按钮
- 电子签署页面：列表增加来源标识（劳动合同/离职协议）
- 合同卡片：电子签署合同显示提示而非手动填写编号/链接

frontend/src/pages/Termination.tsx

@@ -2,12 +2,12 @@ import { useState, useMemo, useEffect } from 'react'
 import { usePageSize } from '../hooks/usePageSize'
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
 import { toast } from 'sonner'
-import { AlertTriangle, Check, ChevronRight, ChevronLeft, Shield, Info, Calculator, FileText, Printer, Trash2, List, Download, Plus, Edit, Send, CheckCircle, XCircle, Play, Ban, CheckCheck } from 'lucide-react'
+import { AlertTriangle, Check, ChevronRight, ChevronLeft, Shield, Info, Calculator, FileText, Printer, Trash2, List, Download, Plus, Edit, Send, CheckCircle, XCircle, Play, Ban, CheckCheck, PenTool } from 'lucide-react'
 import { Stepper } from '../components/ui/Stepper'
 import { InlineAlert } from '../components/ui/InlineAlert'
 import PageGuide from '../components/ui/PageGuide'
 import jsPDF from 'jspdf'
-import { rosterApi, terminationApi } from '../lib/api-services'
+import { rosterApi, terminationApi, esignApi } from '../lib/api-services'
 import { useAuthStore } from '../store/authStore'
 import Card from '../components/ui/Card'
 import Button from '../components/ui/Button'
@@ -1549,6 +1549,27 @@ export default function Termination() {
                   placeholder="备注说明（选填）"
                   className="text-xs"
                 />
+                {item.key === 'docs_signed' && employeeId && (
+                  <Button
+                    size="sm"
+                    variant="secondary"
+                    onClick={async () => {
+                      try {
+                        await esignApi.create({
+                          employeeId,
+                          documentTitle: '离职协议',
+                          remark: '离职流程中发起',
+                        })
+                        queryClient.invalidateQueries({ queryKey: ['esign-records'] })
+                        toast.success('离职协议电子签署已发起')
+                      } catch {
+                        toast.error('发起签署失败')
+                      }
+                    }}
+                  >
+                    <PenTool className="w-3.5 h-3.5 mr-1" />发起电子签署
+                  </Button>
+                )}
               </div>
             ))}
             <div className="flex items-center gap-2 text-xs text-gray-500">