完善借款、编号、付款与预算并发及验收（09-06-release-gate-integrity）

汇总已落盘的借款本金与还款、兼容历史编号的周期化编号、付款责任与回单核验、报销进度和排序、PWA/采购事务、错误原因与日期校验及ERP退役。
统一共享预算池锁序和锁后判断，恢复差旅原预算选择，补原因码固定夹具及反向完整性检查。
纳入配套迁移、测试、受管QA、分层验收合同、规约及任务记录；原始证据留在ignored artifacts。

关联任务：09-17-company-loan-principal-repayment、09-17-erp-exclusive-retirement、09-18-reimbursement-periodic-numbering、09-08-reimbursement-payment-closeout、09-18-local-concurrency-product-fixes、09-19-budget-pool-concurrency、09-05-error-explainability-payment-readiness。
预算补审由Claude定向验证2文件928项通过，原4446/28及r6结果仍仅对应各自历史输入；本轮未重跑测试。
完整新候选门禁、R1真实入口接入与12项公网义务仍开放。生产编号未启用、差旅仍冻结；不推送、不部署，不宣称发布资格。

server/tests/unit/routes/exports.presence.test.js

@@ -240,7 +240,7 @@ describe("presence history exports route", () => {
     });
 
     expect(response.statusCode).toBe(409);
-    expect(response.json().error.details).toEqual({ export: "too_large" });
+    expect(response.json().error.details).toEqual({ export: "too_large", reasonCode: "export.presence_too_large" });
     expect(auditCreate).not.toHaveBeenCalled();
 
     await app.close();
@@ -265,3 +265,42 @@ describe("presence history exports route", () => {
     await app.close();
   });
 });
+
+
+describe("presence export calendar boundaries", () => {
+  it.each(["dateFrom", "dateTo"])("rejects overflowing %s without export audit or employee reads", async (field) => {
+    const { app, employeeFindMany, auditCreate } = await buildApp();
+    try {
+      const response = await app.inject({ method: "GET", url: `/api/exports/presence-history?${field}=2026-04-31` });
+      expect(response.statusCode).toBe(400);
+      expect(employeeFindMany).not.toHaveBeenCalled();
+      expect(auditCreate).not.toHaveBeenCalled();
+    } finally { await app.close(); }
+  });
+});
+
+
+describe("presence history range reasons", () => {
+  it.each([
+    ["2024-03-01", "2024-02-29", "presence_history.date_range_invalid", { dateTo: "must_be_after_or_equal_dateFrom" }],
+    ["2024-01-01", "2024-02-01", "presence_history.date_range_too_large", { dateRange: "too_large" }],
+  ])("explains %s..%s before employee queries", async (from, to, reasonCode, details) => {
+    const { app, employeeFindMany, auditCreate } = await buildApp();
+    try {
+      const response = await app.inject({ method: "GET", url: `/api/exports/presence-history?dateFrom=${from}&dateTo=${to}` });
+      expect(response.statusCode).toBe(400);
+      expect(response.json().error).toMatchObject({ code: "VALID_001", details: { ...details, reasonCode } });
+      expect(response.json().error.details).toEqual({ ...details, reasonCode });
+      expect(employeeFindMany).not.toHaveBeenCalled();
+      expect(auditCreate).not.toHaveBeenCalled();
+    } finally { await app.close(); }
+  });
+  it("keeps exactly 31 inclusive days valid", async () => {
+    const { app, employeeFindMany } = await buildApp();
+    try {
+      const response = await app.inject({ method: "GET", url: "/api/exports/presence-history?dateFrom=2024-01-01&dateTo=2024-01-31" });
+      expect(response.statusCode).toBe(200);
+      expect(employeeFindMany).toHaveBeenCalled();
+    } finally { await app.close(); }
+  });
+});