fix: 解聘保存后根据解聘日期判断在职/离职状态

- 解聘日期<=今天：员工状态设为RESIGNED（离职）
- 解聘日期>今天：员工状态保持ACTIVE（在职，未到解聘日）

backend/src/services/termination.service.ts

@@ -157,9 +157,15 @@ export async function createTermination(orgId: string, userId: string, data: any
     },
   })
 
+  // 根据解聘日期判断在职/离职状态
+  const termDate = new Date(data.terminationDate)
+  const today = new Date()
+  today.setHours(0, 0, 0, 0)
+  const isResigned = termDate <= today
+
   await prisma.employee.update({
     where: { id: data.employeeId },
-    data: { status: 'RESIGNED' },
+    data: { status: isResigned ? 'RESIGNED' : 'ACTIVE' },
   })
 
   await prisma.riskItem.updateMany({