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/services/paymentOrderXls.test.js

@@ -63,6 +63,19 @@ describe("payment order BIFF8 generator", () => {
     expect(result.totalAmount).toBe("3.20");
   });
 
+  it("exports principal repayment as one transfer with decrypted account name and repayment purpose", () => {
+    const batch = buildBatch({ entity_type: "loan_repayment" });
+    batch.items = [batch.items[0]];
+    batch.items[0].entity_code = "HK-SYNTHETIC";
+    batch.items[0].snapshot_json.payee.name = "合***";
+    batch.items[0].snapshot_json.payee.accountNameEncrypted = encrypt("合成出借人");
+    const row = buildPaymentOrderRows(config, batch).rows[0];
+    expect(row[5]).toBe("合成出借人");
+    expect(row.slice(10, 12)).toEqual(["还款", "归还借款本金"]);
+    batch.items[0].snapshot_json.payee.accountNameEncrypted = "invalid";
+    expect(() => buildPaymentOrderRows(config, batch)).toThrow();
+  });
+
   it("preserves complete names and document codes without truncation", () => {
     const batch = buildBatch();
     const name = "合成姓名".repeat(20);
@@ -270,3 +283,17 @@ describe("payment order BIFF8 generator", () => {
     }
   });
 });
+
+it("keeps customer serial and business row identity with an annual PB and mixed source formats", () => {
+  const batch = buildBatch({ batch_no: "PB-2026-0001" });
+  batch.items[0].entity_code = "BX-202609-0001";
+  const original = structuredClone(batch);
+  const rows = buildPaymentOrderRows(config, batch);
+  expect(rows.serials).toEqual(["PB-2026-0001-R001", "PB-2026-0001-R002"]);
+  const reversed = buildPaymentOrderRows(config, { ...batch, items: [...batch.items].reverse() });
+  expect(reversed).toEqual(rows);
+  expect(batch).toEqual(original);
+  const workbook = generatePaymentOrderXls(config, batch);
+  expect(workbook.serials).toEqual(rows.serials);
+  expect(workbook.buffer.subarray(0, 8).toString("hex")).toBe("d0cf11e0a1b11ae1");
+});