fix: 加固日历日期与动态错误合同（09-05-error-explainability-payment-readiness，09-08-reimbursement-payment-closeout）

server/tests/unit/routes/travelRequests.test.js

@@ -128,6 +128,19 @@ async function buildApp({ employee, prisma }) {
 }
 
 describe("travelRequests routes", () => {
+  it.each(["startDate", "endDate"])("rejects overflowing %s before the edit transaction", async (field) => {
+    const prisma = { $transaction: vi.fn() };
+    const app = await buildApp({ employee: { id: "employee-1", permissionCodes: ["travel.create"] }, prisma });
+    try {
+      const response = await app.inject({ method: "PATCH", url: "/api/travel-requests/11111111-1111-4111-8111-111111111111",
+        headers: { authorization: "Bearer test" }, payload: { [field]: "2026-04-31" } });
+      expect(response.statusCode).toBe(400);
+      expect(response.json().error.code).toBe("VALID_001");
+      expect(response.json().error.details.fieldErrors[field]).toContain("invalid_calendar_date");
+      expect(prisma.$transaction).not.toHaveBeenCalled();
+    } finally { await app.close(); }
+  });
+
   it("lists only own records when actor lacks view_all", async () => {
     const prisma = buildPrisma({
       items: [buildTravelRequestRecord()],