feat: 社保公积金独立配置+版本化缴费记录+月度增减员+补偿金批次

- Schema: 拆分社保/公积金配置，新增EmployeeSocialInsRecord/EmployeeHousingFundRecord/DepartmentRecord模型，扩展SalaryChangeRecord，增加SEVERANCE批次类型
- 后端: createEmployee/rehireEmployee接收社保公积金字段并创建缴费记录版本；createTermination/createResignation接收截止年月并关闭缴费记录；调薪/调部门API+版本记录；月度增减员API；公积金独立CRUD/计算/调基；SEVERANCE批次calcBatchEntry
- 前端: AddEmployeeModal/RehireModal增加社保公积金输入；ResignModal/Termination增加截止年月+日期不一致提醒；花名册增加调薪/调部门弹窗；SocialInsurance.tsx Tab拆分(社保/公积金/月度增减员)+CSV导出；Money.tsx增加补偿金批次类型
- 修复: seed.ts移除housingOrg/housingEmp；risk.service.ts从HousingFundConfig获取公积金费率

frontend/src/pages/Termination.tsx

@@ -56,6 +56,8 @@ export default function Termination() {
   const [reason, setReason] = useState('')
   const [employeeId, setEmployeeId] = useState('')
   const [terminationDate, setTerminationDate] = useState('')
+  const [socialInsEndMonth, setSocialInsEndMonth] = useState('')
+  const [housingFundEndMonth, setHousingFundEndMonth] = useState('')
   const [checklist, setChecklist] = useState<Record<string, boolean>>({})
   const [acknowledgeRisk, setAcknowledgeRisk] = useState(false)
   const [socialAvgWage, setSocialAvgWage] = useState(0)
@@ -289,6 +291,8 @@ export default function Termination() {
       employeeId,
       reason,
       terminationDate: new Date(terminationDate).toISOString(),
+      socialInsEndMonth: socialInsEndMonth || terminationDate.slice(0, 7),
+      housingFundEndMonth: housingFundEndMonth || terminationDate.slice(0, 7),
       compensation: costResult?.totalSeverance || 0,
       checklist,
       remark: '',
@@ -394,6 +398,8 @@ export default function Termination() {
     setReason('')
     setEmployeeId('')
     setTerminationDate('')
+    setSocialInsEndMonth('')
+    setHousingFundEndMonth('')
     setChecklist({})
     setAcknowledgeRisk(false)
   }
@@ -523,6 +529,26 @@ export default function Termination() {
               <Label>解聘日期</Label>
               <Input type="date" value={terminationDate} onChange={(e) => setTerminationDate(e.target.value)} />
             </div>
+            <div className="border-t pt-3">
+              <Label>社保公积金截止缴费年月</Label>
+              <div className="text-xs text-gray-400 mb-2">默认与解聘日期同月，可手动修改</div>
+              <div className="grid grid-cols-2 gap-3">
+                <div>
+                  <Label>社保截止年月</Label>
+                  <Input type="month" value={socialInsEndMonth || terminationDate.slice(0, 7)} onChange={(e) => setSocialInsEndMonth(e.target.value)} />
+                </div>
+                <div>
+                  <Label>公积金截止年月</Label>
+                  <Input type="month" value={housingFundEndMonth || terminationDate.slice(0, 7)} onChange={(e) => setHousingFundEndMonth(e.target.value)} />
+                </div>
+              </div>
+              {terminationDate && ((socialInsEndMonth && socialInsEndMonth !== terminationDate.slice(0, 7)) || (housingFundEndMonth && housingFundEndMonth !== terminationDate.slice(0, 7))) && (
+                <div className="flex items-center gap-2 px-3 py-2 rounded-md bg-amber-50 text-warning text-xs mt-2">
+                  <AlertTriangle className="w-4 h-4 shrink-0" />
+                  截止缴费年月与解聘日期不在同月，请确认是否为多缴/少缴月份。
+                </div>
+              )}
+            </div>
 
             {/* 禁止解聘检查 */}
             {riskAssessment && riskAssessment.warnings.length > 0 && (