采购提交与报销新建/提交事务显式使用10秒上限 [09-27-purchase-submit-tx-timeout]

负载下采购提交事务超过 Prisma 交互事务默认 5000ms（P2028）返回 500。
分段计时显示无单一瓶颈（总时长中位 843ms、最大 3506ms，编号锁等待
最多 535ms），是约 20 条顺序查询整体变慢贴近上限。报销新建/提交同结构。
三处改用项目既有的 { maxWait: 5000, timeout: 10000 }，事务内容不变；
新增采购与报销提交的事务选项回归断言。

Co-Authored-By: Claude Opus 5.5 <[email protected]>

server/src/routes/purchaseRequests.js

@@ -1701,6 +1701,8 @@ async function purchaseRequestRoutes(fastify, options = {}) {
         throw buildBusinessValidationError("purchase_request.approver_unavailable", { workflow: "no_actionable_approver" }, 409);
       }
 
+      // ~20 sequential queries plus document numbering; under load this exceeded
+      // Prisma's 5s interactive-transaction default (P2028 -> 500).
       const submitResult = await fastify.prisma.$transaction(async (tx) => {
         const locked = await loadPurchaseRequestForUpdate(tx, purchaseRequestId);
         ensureDraftOwner(request, locked);
@@ -1949,7 +1951,7 @@ async function purchaseRequestRoutes(fastify, options = {}) {
             budgetReservation,
           },
         };
-      });
+      }, { maxWait: 5000, timeout: 10000 });
 
       void fastify.prisma.auditLog.create({
         data: buildAuditLogData(request, {

server/src/routes/reimbursements.js

@@ -1863,7 +1863,7 @@ async function reimbursementRoutes(fastify) {
           ...created,
           items: createdItems,
         };
-      });
+      }, { maxWait: 5000, timeout: 10000 });
 
       return sendData(reply, request, {
         id: reimbursement.id,
@@ -4498,7 +4498,7 @@ async function reimbursementRoutes(fastify) {
             actorId: request.employee.id,
           },
         };
-      });
+      }, { maxWait: 5000, timeout: 10000 });
 
       await finalizeReimbursementSubmitSideEffects({
         prisma: fastify.prisma,