feat: 员工端新增个人资料页面，数据同步到花名册

- 后端新增 GET/PUT /portal/profile 接口，员工可查看和编辑个人资料
- 员工可编辑：紧急联系人、住址、银行卡、学历、参保城市
- 只读字段：姓名、性别、手机号、证件号码、部门、岗位、入职日期
- 数据直接写入 Employee 表（花名册），HR 管理端可见
- 更新操作记录证据链（PROFILE_UPDATE）
- 前端新增 MyProfile.tsx 页面，PortalNav 添加导航入口

frontend/src/App.tsx

@@ -58,6 +58,7 @@ const OnboardingProgress = lazyRetry(() => import('./pages/portal/OnboardingProg
 const ResignationApply = lazyRetry(() => import('./pages/portal/ResignationApply'))
 const MyEsign = lazyRetry(() => import('./pages/portal/MyEsign'))
 const MyRecords = lazyRetry(() => import('./pages/portal/MyRecords'))
+const MyProfile = lazyRetry(() => import('./pages/portal/MyProfile'))
 const RiskCenter = lazyRetry(() => import('./pages/compliance/RiskCenter'))
 const SalaryDashboard = lazyRetry(() => import('./pages/SalaryDashboard'))
 const CommercialInsurance = lazyRetry(() => import('./pages/CommercialInsurance'))
@@ -247,6 +248,7 @@ export default function App() {
       <Route path="/portal/resignation" element={<PortalLayoutWrapper><ResignationApply /></PortalLayoutWrapper>} />
       <Route path="/portal/esign" element={<PortalLayoutWrapper><MyEsign /></PortalLayoutWrapper>} />
       <Route path="/portal/records" element={<PortalLayoutWrapper><MyRecords /></PortalLayoutWrapper>} />
+      <Route path="/portal/profile" element={<PortalLayoutWrapper><MyProfile /></PortalLayoutWrapper>} />
 
       {/* 兜底 */}
       <Route path="*" element={<Navigate to="/" replace />} />