From 734153847b8d2ec62f98a474f890913921e86555 Mon Sep 17 00:00:00 2001
From: shunli <shunli@qq.com>
Date: Thu, 30 Jul 2026 14:41:08 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8D=E6=8A=A5=E9=94=80=E9=99=84?=
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MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../spec/hyb-oa/reimbursement-invoice-ocr.md  | 92 ++++++++++++++++++
 .../design.md                                 |  9 ++
 .../implement.md                              | 16 ++++
 .../07-28-travel-reimbursement-guide/prd.md   |  9 ++
 client/src/api/errorMessages.ts               |  6 ++
 client/src/api/reimbursements.ts              |  2 +
 .../pages/MobileReimbursementDetailPage.tsx   | 17 +++-
 client/src/pages/ReimbursementDetailPage.tsx  | 17 +++-
 server/src/routes/invoicePool/read.js         |  8 +-
 server/src/routes/reimbursements.js           | 23 +++--
 .../src/services/purchaseAttachmentPolicy.js  | 50 ++--------
 server/src/utils/contentDisposition.js        | 67 +++++++++++++
 .../unit/routes/invoicePool.file.test.js      | 80 ++++++++++++++++
 .../routes/reimbursements.attachments.test.js | 94 ++++++++++++++++++-
 .../services/purchaseAttachmentPolicy.test.js |  9 ++
 15 files changed, 434 insertions(+), 65 deletions(-)
 create mode 100644 server/src/utils/contentDisposition.js
 create mode 100644 server/tests/unit/routes/invoicePool.file.test.js

diff --git a/.trellis/spec/hyb-oa/reimbursement-invoice-ocr.md b/.trellis/spec/hyb-oa/reimbursement-invoice-ocr.md
index 4ae22146..a4e16509 100644
--- a/.trellis/spec/hyb-oa/reimbursement-invoice-ocr.md
+++ b/.trellis/spec/hyb-oa/reimbursement-invoice-ocr.md
@@ -473,6 +473,98 @@ const TRAVEL_TRANSPORT_EXPENSE_TYPE_CODES = { bus: "travel_bus" };
 // model and fee-control service both support eligible-day multiplication.
 ```
 
+## Scenario: Reimbursement Attachment Batch And UTF-8 Filename Boundary
+
+### 1. Scope / Trigger
+
+- Trigger: changing reimbursement supporting-material upload limits, multipart
+  parsing, attachment/invoice file responses or tests that register multipart.
+- Purpose: preserve the global one-file safety default while supporting the
+  reimbursement UI's bounded multi-file request and legal Chinese file names.
+
+### 2. Signatures
+
+- Upload: `POST /api/reimbursements/:id/attachments`, multipart field `files`,
+  one to five PDF/JPG/PNG/WebP files per request.
+- Route parser: `request.parts({ limits: { files: 5, fileSize } })`; the global
+  `@fastify/multipart` registration remains `limits.files=1`.
+- Download headers: `buildAttachmentContentDisposition(name, {
+  disposition: "inline" })` for reimbursement attachments and invoice PDFs.
+- Client constant: `MAX_REIMBURSEMENT_ATTACHMENT_FILES=5` is shared by PC and
+  mobile reimbursement detail pages.
+
+### 3. Contracts
+
+- Do not relax the application-wide multipart file count. Only the
+  reimbursement supporting-material route overrides it to five.
+- Parse the complete multipart request before storage/database writes so a
+  sixth file cannot leave a partial five-file upload.
+- `FST_FILES_LIMIT` maps to `400 VALID_001` with
+  `{ file: "too_many_files", maxFiles: 5 }`; PC and mobile show the same
+  bounded message. Generic error mapping must not assume every module has the
+  reimbursement limit when `maxFiles` is absent.
+- Preserve the original name in the database. HTTP `Content-Disposition` uses
+  an ASCII `filename` fallback plus RFC 5987 UTF-8 `filename*`; never place raw
+  Chinese, CR/LF, quotes, path separators or control characters in the legacy
+  quoted parameter.
+- Reimbursement attachments and invoice PDFs retain `inline`; purchase,
+  employee and payment receipt downloads keep their existing default
+  `attachment` behavior through the same shared builder.
+
+### 4. Validation & Error Matrix
+
+- One to five allowed files -> parse and persist all files.
+- Six or more files -> `400 VALID_001 / file=too_many_files`, with zero storage,
+  database and audit writes.
+- Unsupported MIME, empty file or oversized file -> existing stable file
+  validation error; no partial persistence.
+- Chinese name -> `inline; filename="attachment.<ext>"; filename*=UTF-8''...`.
+- Invalid disposition value -> `TypeError`; callers may use only `inline` or
+  `attachment`.
+
+### 5. Good/Base/Bad Cases
+
+- Good: PC selects five payment screenshots; the route succeeds even though
+  the test app and production app both register global `files=1`.
+- Base: one ASCII PDF keeps an ASCII fallback and an equivalent `filename*`.
+- Bad: set the test-only global limit to five, which hides a missing route
+  override; or interpolate a Chinese database name directly into a Node header.
+
+### 6. Tests Required
+
+- Register multipart with the production global `files=1` in reimbursement
+  route tests, then assert five files succeed.
+- Send six files and assert `400`, `VALID_001`, `too_many_files`, and no
+  attachment/audit writes.
+- Download an existing Chinese-name reimbursement attachment and invoice PDF;
+  assert `inline`, ASCII `filename`, percent-encoded `filename*`, and no raw
+  Chinese in the header.
+- Cover CR/LF, quote and path cleanup in the shared Content-Disposition helper,
+  while retaining existing purchase `attachment` regression tests.
+- Run backend full tests and frontend typecheck/build because the limit and
+  error message cross API and both UI variants.
+
+### 7. Wrong vs Correct
+
+#### Wrong
+
+```js
+await fastify.register(multipart, { limits: { files: 5 } }); // test-only drift
+reply.header("content-disposition", `inline; filename="${originalName}"`);
+```
+
+#### Correct
+
+```js
+for await (const part of request.parts({ limits: { files: 5, fileSize } })) {
+  // Buffer and validate the bounded request before persistence.
+}
+reply.header(
+  "content-disposition",
+  buildAttachmentContentDisposition(originalName, { disposition: "inline" }),
+);
+```
+
 ## Scenario: Payment Batch Receipt Attention Count
 
 ### 1. Scope / Trigger
diff --git a/.trellis/tasks/07-28-travel-reimbursement-guide/design.md b/.trellis/tasks/07-28-travel-reimbursement-guide/design.md
index cfa5ffaf..8465cb76 100644
--- a/.trellis/tasks/07-28-travel-reimbursement-guide/design.md
+++ b/.trellis/tasks/07-28-travel-reimbursement-guide/design.md
@@ -68,6 +68,15 @@
 - 当前 `ReimbursementItem` 没有天数或数量字段，`ExpenseStandard.per_unit=day` 也不会在费用控制中乘以天数。因此本轮不创建 100/80 元 block 或 warn 标准，员工分别新增补助明细，以“天数 × 单价”人工算出总额并在说明写明计算式，由主管和财务复核。
 - 自动带出差旅起止日、计算符合条件的补助天数以及按天校验属于后续产品能力，不阻塞本次真实报销。
 
+## 报销附件上传与中文文件名
+
+- 生产复现显示 PC 一次发送多个补充附件时触发 `FST_FILES_LIMIT`：全局 multipart 合同为 `files=1`，而报销附件路由、PC/手机页面和既有测试均按多文件设计。测试曾把全局上限改成 5，掩盖了生产差异。
+- 保持全局 `files=1`，仅在报销附件 `request.parts()` 调用传入 `limits.files=5` 和既有文件大小限制；捕获 `FST_FILES_LIMIT` 并映射为 `VALID_001 / file=too_many_files`。
+- 客户端共享 `MAX_REIMBURSEMENT_ATTACHMENT_FILES=5`，PC 与手机选择后先拦截超限并显示相同提示；API 仍接受数组，单次请求最多 5 个。
+- 生产还复现了中文附件打开失败：原实现仅替换 CR/LF/引号，仍把中文直接放进 `filename="..."`，Node 以 `ERR_INVALID_CHAR` 拒绝响应头。
+- 把现有采购附件的安全 Content-Disposition 构造能力提炼/扩展为可选 `attachment` 或 `inline` 处置类型，生成安全 ASCII `filename` 与 RFC 5987 UTF-8 `filename*`。报销附件与发票 PDF 使用 `inline`；采购、回单等既有 `attachment` 调用保持不变。
+- 不改变文件原名在数据库中的业务展示值，不重写已上传文件；修复部署后既有中文名附件即可正常打开。
+
 ## 失败与回退
 
 - adapter 聚焦测试、配置 smoke、腾讯调用或任一真实样票验证失败：停止开放真实票据，不继续制造 pending/retry 数据。
diff --git a/.trellis/tasks/07-28-travel-reimbursement-guide/implement.md b/.trellis/tasks/07-28-travel-reimbursement-guide/implement.md
index a38da07b..980e8e1e 100644
--- a/.trellis/tasks/07-28-travel-reimbursement-guide/implement.md
+++ b/.trellis/tasks/07-28-travel-reimbursement-guide/implement.md
@@ -70,6 +70,22 @@
 - [x] 明确当前由员工按“天数 × 单价”人工填写总额；不配置会误判多日补助的单条费用标准。
 - [x] 重新生成并检查一页版差旅报销 PDF。
 
+## 5.2 真实首笔报销附件阻断修复
+
+- [x] 报销附件路由显式支持单次最多 5 个文件，并稳定映射 `FST_FILES_LIMIT`。
+- [x] PC/手机共享最多 5 个文件的选择限制、提示和客户端拦截。
+- [x] 报销附件与发票 PDF 使用安全 ASCII fallback + RFC 5987 UTF-8 文件名响应头。
+- [x] 测试恢复生产全局 `files=1`，覆盖路由级 5 个成功、6 个失败、中文名及头注入清理。
+- [x] 完成后端、前端、流程、文档、敏感内容和 Trellis 门禁；提交后另行取得生产部署批准。
+
+## 2026-07-30 报销附件阻断修复验证
+
+- 生产日志根因已由聚焦回归锁定：PC 多文件请求触发全局 `FST_FILES_LIMIT`，中文原名直接进入响应头触发 `ERR_INVALID_CHAR`；手机并非独立后端链路。
+- 报销附件路由保持生产全局 `files=1` 基线并局部覆盖为 5；第 6 个文件返回 `400 VALID_001 / too_many_files`，且附件和审计写入均为 0。
+- 报销附件与发票 PDF 已统一使用安全 `inline` Content-Disposition；采购、员工附件和付款回单仍保持默认 `attachment`。
+- 聚焦测试 3 个文件/47 项、后端全量 169 个文件/1082 项、Prisma validate、前端 typecheck/build、流程合同、文档审计、Trellis governance、敏感内容、task validate 与 `git diff --check` 均通过；文档审计仅保留 22 个既有未注册文档 warning。
+- 本地修复尚未提交、推送或部署；只有部署并完成公网与 PC/手机实测后，才能通知用户重新验收。
+
 ## 6. 验证与审查
 
 - [x] 静态核对页面/API 上传格式、明细绑定和员工/财务字段边界。
diff --git a/.trellis/tasks/07-28-travel-reimbursement-guide/prd.md b/.trellis/tasks/07-28-travel-reimbursement-guide/prd.md
index 9992ccd1..7be626db 100644
--- a/.trellis/tasks/07-28-travel-reimbursement-guide/prd.md
+++ b/.trellis/tasks/07-28-travel-reimbursement-guide/prd.md
@@ -27,6 +27,7 @@
 - 配置并正式启用生产腾讯 OCR，完成配置门禁、受控发布、公网检查和授权 PDF 样票验证。
 - 在现有腾讯 provider 内改用通用票据识别高级版，补齐住宿电子普通发票和铁路电子客票的安全归一化、质量门禁、大小限制和测试。
 - 固化公司差旅补助规定，补齐不与城际大巴费用混淆的费用类型，并同步员工指南和报销事实源。
+- 修复真实首笔报销暴露的 PC 多附件上传与中文文件名打开失败，保持 PC/手机和生产 multipart 合同一致。
 
 ## Requirements
 
@@ -54,6 +55,10 @@
 - 公司或其他单位已直接承担餐食或车辆费用的，不重复领取相应补助；城际交通、住宿及其他经批准的必要差旅费用凭有效材料实报实销。
 - 当前报销明细没有天数字段，两项补助分别作为独立明细人工填写总额和计算式，例如“伙食补助费：3 天 × 100 元”；不得把现有 `per_unit=day` 费用标准直接配置为 100/80 元，因为当前校验不会按天数乘算，会误判多日补助。
 - `travel_bus` 保留为城际大巴车票费用；市内交通补助使用独立费用类型，不得共用代码或混同展示。
+- 报销补充附件在 PC 与手机端均允许单次选择 1–5 个文件；服务端必须在该路由显式覆盖全局单文件 multipart 上限，第 6 个文件进入稳定的 `VALID_001` 错误，不得退化成 `SYS_001`。
+- PC 与手机选择器均显示“单次最多 5 个”，并在请求前拦截超过 5 个文件的选择；客户端限制只改善体验，服务端仍是最终边界。
+- 报销附件和发票 PDF 的中文原文件名不得直接进入 HTTP 响应头；`Content-Disposition` 使用安全 ASCII fallback 与 RFC 5987 `filename*`，同时清理控制字符、路径和响应头注入字符。
+- 报销附件继续使用 `inline` 语义，发票 PDF 继续支持当前预览/下载流程；修复不得改变附件权限、用途留痕、审计或存储内容。
 - 文档不放真实票据、支付截图、账号、订单号、银行信息或完整业务数据。
 
 ## Acceptance Criteria
@@ -71,12 +76,16 @@
 - [x] 未配置会把多日补助误判为超标的 100/80 元单条费用标准；指南要求员工按天数人工计算并在说明中写出算式。
 - [x] 在真实 OCR 验收完成前不得仅因指南已完成就通知杨俊可以提交。
 - [x] 全程不把真实票据、支付截图、完整账号、银行资料、Secret 或原始 payload 写入仓库、任务或聊天。
+- [x] PC 与手机均可一次上传 1–5 个报销补充附件；选择第 6 个时客户端提前提示，绕过客户端直调服务端仍返回稳定 `VALID_001` 而非 500。
+- [x] 中文文件名的报销附件和发票 PDF 均返回合法 `Content-Disposition`，保留 `inline` 与 UTF-8 文件名语义且无响应头注入。
+- [x] 聚焦测试使用与生产一致的全局 `files=1` 基线，证明路由级覆盖有效，并覆盖 5 个成功、6 个失败、中文名和恶意文件名。
 
 ## Out of Scope
 
 - 新增第二个 OCR provider、开放图片发票、自动验真或增加人工发票字段。
 - 本轮不做通用发票平台或覆盖全部票种；仅支持现有住宿 VAT/电子普通发票和电子发票（铁路电子客票）主路径。
 - 修改报销页面、上传格式、审批规则或自动按天计算；本轮只调整差旅相关费用类型名称并新增独立的市内交通补助类型，不配置 100/80 元费用标准。
+- 改变全局 multipart 单文件默认值，或放宽发票上传“一份请求一张正式票据”的边界。
 - 代替杨俊上传票据、创建报销、提交审批，或代替主管/财务处理。
 - 制定覆盖所有费用类别的完整财务制度；本轮只收口首笔差旅的实报实销材料和两项包干补助。
 
diff --git a/client/src/api/errorMessages.ts b/client/src/api/errorMessages.ts
index e667b01c..de149f11 100644
--- a/client/src/api/errorMessages.ts
+++ b/client/src/api/errorMessages.ts
@@ -359,6 +359,12 @@ export function mapApiErrorMessage(
       return "附件超过大小限制，请压缩后重新上传。";
     }
 
+    if (details?.file === "too_many_files") {
+      return details?.maxFiles === 5
+        ? "单次最多上传 5 个附件，请分批上传。"
+        : "一次选择的附件过多，请减少数量后分批上传。";
+    }
+
     if (details?.file === "dangerous_filename") {
       return "附件名称不安全，请重命名后重新上传。";
     }
diff --git a/client/src/api/reimbursements.ts b/client/src/api/reimbursements.ts
index 83cce450..73715795 100644
--- a/client/src/api/reimbursements.ts
+++ b/client/src/api/reimbursements.ts
@@ -490,6 +490,8 @@ export async function deleteReimbursementItem(reimbursementId: string, itemId: s
   );
 }
 
+export const MAX_REIMBURSEMENT_ATTACHMENT_FILES = 5;
+
 export async function uploadReimbursementAttachments(reimbursementId: string, files: File[]) {
   const formData = new FormData();
   for (const file of files) {
diff --git a/client/src/pages/MobileReimbursementDetailPage.tsx b/client/src/pages/MobileReimbursementDetailPage.tsx
index 1a75ba5a..87777f7f 100644
--- a/client/src/pages/MobileReimbursementDetailPage.tsx
+++ b/client/src/pages/MobileReimbursementDetailPage.tsx
@@ -20,6 +20,7 @@ import {
   deleteReimbursementItem,
   downloadReimbursementAttachment,
   fetchReimbursementDetail,
+  MAX_REIMBURSEMENT_ATTACHMENT_FILES,
   precheckReimbursement,
   submitReimbursement,
   updateReimbursementItem,
@@ -678,6 +679,9 @@ export function MobileReimbursementDetailPage() {
       if (!files.length) {
         throw new Error("请选择附件材料");
       }
+      if (files.length > MAX_REIMBURSEMENT_ATTACHMENT_FILES) {
+        throw new Error(`单次最多上传 ${MAX_REIMBURSEMENT_ATTACHMENT_FILES} 个附件，请分批上传。`);
+      }
       return uploadReimbursementAttachments(reimbursementId, files);
     },
     onSuccess: async () => {
@@ -1088,7 +1092,7 @@ export function MobileReimbursementDetailPage() {
         <div className="flex items-center justify-between gap-3">
           <div>
             <h2 className="text-base font-semibold text-zinc-900">附件材料</h2>
-            <p className="mt-1 text-xs text-zinc-500">合同、订单、付款截图或情况说明</p>
+            <p className="mt-1 text-xs text-zinc-500">PDF/JPG/PNG/WebP，单次最多 5 个</p>
           </div>
           {canManageAttachments ? (
             <Button
@@ -1110,7 +1114,16 @@ export function MobileReimbursementDetailPage() {
               type="file"
               accept="application/pdf,image/jpeg,image/png,image/webp"
               multiple
-              onChange={(event) => setSelectedAttachmentFiles(Array.from(event.target.files ?? []))}
+              onChange={(event) => {
+                const files = Array.from(event.target.files ?? []);
+                if (files.length > MAX_REIMBURSEMENT_ATTACHMENT_FILES) {
+                  setSelectedAttachmentFiles([]);
+                  event.target.value = "";
+                  toast.error(`单次最多上传 ${MAX_REIMBURSEMENT_ATTACHMENT_FILES} 个附件，请分批上传。`);
+                  return;
+                }
+                setSelectedAttachmentFiles(files);
+              }}
             />
             {selectedAttachmentFiles.length ? (
               <div className="rounded-lg border border-zinc-200 bg-zinc-50 px-3 py-2 text-xs text-zinc-600">
diff --git a/client/src/pages/ReimbursementDetailPage.tsx b/client/src/pages/ReimbursementDetailPage.tsx
index 3c098436..b8039ef2 100644
--- a/client/src/pages/ReimbursementDetailPage.tsx
+++ b/client/src/pages/ReimbursementDetailPage.tsx
@@ -13,6 +13,7 @@ import {
   deleteReimbursementItem,
   downloadReimbursementAttachment,
   fetchReimbursementDetail,
+  MAX_REIMBURSEMENT_ATTACHMENT_FILES,
   precheckReimbursement,
   submitReimbursement,
   updateReimbursementItem,
@@ -662,6 +663,9 @@ export function ReimbursementDetailPage() {
       if (!files.length) {
         throw new Error("请选择附件材料");
       }
+      if (files.length > MAX_REIMBURSEMENT_ATTACHMENT_FILES) {
+        throw new Error(`单次最多上传 ${MAX_REIMBURSEMENT_ATTACHMENT_FILES} 个附件，请分批上传。`);
+      }
       return uploadReimbursementAttachments(reimbursementId, files);
     },
     onSuccess: async () => {
@@ -1496,7 +1500,7 @@ export function ReimbursementDetailPage() {
                 <div className="flex flex-col gap-3 md:flex-row md:items-center md:justify-between">
                   <div className="space-y-1">
                     <h3 className="text-base font-semibold text-zinc-900">补充附件</h3>
-                    <p className="text-xs text-zinc-500">合同、订单、支付截图或情况说明；敏感附件下载会要求填写用途。</p>
+                    <p className="text-xs text-zinc-500">合同、订单、支付截图或情况说明；PDF/JPG/PNG/WebP，单次最多 5 个。</p>
                   </div>
                   {canEditItems ? (
                     <div className="flex flex-col gap-2 md:flex-row md:items-center">
@@ -1516,7 +1520,16 @@ export function ReimbursementDetailPage() {
                         type="file"
                         accept="application/pdf,image/jpeg,image/png,image/webp"
                         multiple
-                        onChange={(event) => setSelectedAttachmentFiles(Array.from(event.target.files ?? []))}
+                        onChange={(event) => {
+                          const files = Array.from(event.target.files ?? []);
+                          if (files.length > MAX_REIMBURSEMENT_ATTACHMENT_FILES) {
+                            setSelectedAttachmentFiles([]);
+                            event.target.value = "";
+                            toast.error(`单次最多上传 ${MAX_REIMBURSEMENT_ATTACHMENT_FILES} 个附件，请分批上传。`);
+                            return;
+                          }
+                          setSelectedAttachmentFiles(files);
+                        }}
                       />
                       <Button
                         type="button"
diff --git a/server/src/routes/invoicePool/read.js b/server/src/routes/invoicePool/read.js
index 54afc3ad..6d9cf820 100644
--- a/server/src/routes/invoicePool/read.js
+++ b/server/src/routes/invoicePool/read.js
@@ -4,6 +4,7 @@ const { AppError } = require("../../utils/AppError");
 const { sendData } = require("../../utils/reply");
 const { buildAuditLogData } = require("../../utils/audit");
 const { signPayload, verifyToken } = require("../../utils/signedUrl");
+const { buildAttachmentContentDisposition } = require("../../utils/contentDisposition");
 const { openReadStream, StorageNotFoundError } = require("../../services/storage");
 const { toMoneyString } = require("../../utils/workflow");
 const { resolveInvoiceAvailability } = require("../../services/invoiceGovernance");
@@ -31,11 +32,6 @@ const invoiceStatusQuerySchema = z.object({
   ids: z.string().trim().min(1).max(2000),
 });
 
-function sanitizeFilename(fileName) {
-  if (!fileName) return "file";
-  return fileName.replace(/[\r\n"]/g, "_");
-}
-
 function parseInvoiceListQuery(query) {
   const parsed = invoiceListQuerySchema.safeParse(query ?? {});
   if (!parsed.success) {
@@ -634,7 +630,7 @@ function registerInvoicePoolReadRoutes(fastify) {
     reply.type(invoice.mime_type || "application/octet-stream");
     reply.header(
       "content-disposition",
-      `inline; filename=\"${sanitizeFilename(invoice.original_name)}\"`,
+      buildAttachmentContentDisposition(invoice.original_name, { disposition: "inline" }),
     );
     return reply.send(stream);
   });
diff --git a/server/src/routes/reimbursements.js b/server/src/routes/reimbursements.js
index 2dc8e0d1..f0d4adcd 100644
--- a/server/src/routes/reimbursements.js
+++ b/server/src/routes/reimbursements.js
@@ -6,6 +6,7 @@ const { AppError } = require("../utils/AppError");
 const { sendData } = require("../utils/reply");
 const { buildAuditLogData } = require("../utils/audit");
 const { sha256Hex } = require("../utils/crypto");
+const { buildAttachmentContentDisposition } = require("../utils/contentDisposition");
 const { compactDateString, currentDateString, parseDateOnlyString } = require("../utils/date");
 const { findActiveDelegationForDelegate, listActiveDelegationPrincipals } = require("../utils/delegation");
 const { hasPermission, resolveEntityPermission } = require("../constants/permissions");
@@ -293,11 +294,6 @@ function ensureApplicantOrAdmin(request, reimbursement) {
   }
 }
 
-function sanitizeAttachmentFilename(fileName) {
-  if (!fileName) return "file";
-  return fileName.replace(/[\r\n"]/g, "_");
-}
-
 function mapReimbursementAttachment(item) {
   return {
     id: item.id,
@@ -2481,7 +2477,12 @@ async function reimbursementRoutes(fastify) {
       const files = [];
       let governanceFields = {};
       try {
-        for await (const part of request.parts()) {
+        for await (const part of request.parts({
+          limits: {
+            files: 5,
+            fileSize: fastify.config.maxUploadSizeBytes,
+          },
+        })) {
           if (part.type === "field") {
             governanceFields = parseMultipartGovernanceField(part, governanceFields);
             continue;
@@ -2533,6 +2534,14 @@ async function reimbursementRoutes(fastify) {
           });
         }
       } catch (error) {
+        if (error?.code === "FST_FILES_LIMIT") {
+          throw new AppError({
+            code: "VALID_001",
+            message: "参数校验失败",
+            statusCode: 400,
+            details: { file: "too_many_files", maxFiles: 5 },
+          });
+        }
         if (error?.code === "FST_REQ_FILE_TOO_LARGE") {
           throw new AppError({
             code: "VALID_001",
@@ -2809,7 +2818,7 @@ async function reimbursementRoutes(fastify) {
       reply.type(attachment.mime_type || "application/octet-stream");
       reply.header(
         "content-disposition",
-        `inline; filename=\"${sanitizeAttachmentFilename(attachment.original_name)}\"`,
+        buildAttachmentContentDisposition(attachment.original_name, { disposition: "inline" }),
       );
       return reply.send(stream);
     },
diff --git a/server/src/services/purchaseAttachmentPolicy.js b/server/src/services/purchaseAttachmentPolicy.js
index a01466ed..610a7c34 100644
--- a/server/src/services/purchaseAttachmentPolicy.js
+++ b/server/src/services/purchaseAttachmentPolicy.js
@@ -1,6 +1,7 @@
 const crypto = require("node:crypto");
 
 const sharp = require("sharp");
+const { buildAttachmentContentDisposition: buildContentDisposition } = require("../utils/contentDisposition");
 
 const PURCHASE_ATTACHMENT_MAX_IMAGE_PIXELS = 40_000_000;
 const PURCHASE_ATTACHMENT_MAX_FILE_NAME_CODE_POINTS = 180;
@@ -393,50 +394,11 @@ function buildAttachmentStorageKey(purchaseRequestId, extension) {
   return `purchase-requests/${purchaseRequestId.toLowerCase()}/${crypto.randomUUID()}${extension}`;
 }
 
-function sanitizeHeaderFileName(fileName) {
-  const source = typeof fileName === "string" && fileName.trim()
-    ? fileName.normalize("NFC").trim()
-    : "attachment.bin";
-  const sanitized = truncateCodePoints(
-    source
-      .replace(/[\\/]/gu, "_")
-      .replace(/[\u0000-\u001f\u007f-\u009f]/gu, "_")
-      .replace(/[\u200b-\u200f\u202a-\u202e\u2060-\u2069\ufeff]/gu, "_")
-      .replace(/"+/gu, "_")
-      .replace(/\s+/gu, " ")
-      .trim(),
-    PURCHASE_ATTACHMENT_MAX_FILE_NAME_CODE_POINTS,
-  );
-  return sanitized && sanitized !== "." && sanitized !== ".."
-    ? sanitized
-    : "attachment.bin";
-}
-
-function buildAsciiFallback(fileName) {
-  const lastDotIndex = fileName.lastIndexOf(".");
-  const rawExtension = lastDotIndex > 0 ? fileName.slice(lastDotIndex).toLowerCase() : ".bin";
-  const extension = /^\.[a-z0-9]{1,10}$/u.test(rawExtension) ? rawExtension : ".bin";
-  const rawStem = lastDotIndex > 0 ? fileName.slice(0, lastDotIndex) : fileName;
-  const asciiStem = rawStem
-    .normalize("NFKD")
-    .replace(/[\u0300-\u036f]/gu, "")
-    .replace(/[^a-zA-Z0-9._-]+/gu, "_")
-    .replace(/_+/gu, "_")
-    .replace(/^[._-]+|[._-]+$/gu, "")
-    .slice(0, 100);
-  return `${asciiStem || "attachment"}${extension}`;
-}
-
-function encodeRfc5987Value(value) {
-  return encodeURIComponent(value).replace(/[\u0027\u0028\u0029\u002a]/gu, (character) =>
-    `%${character.charCodeAt(0).toString(16).toUpperCase()}`,
-  );
-}
-
-function buildAttachmentContentDisposition(fileName) {
-  const safeFileName = sanitizeHeaderFileName(fileName);
-  const asciiFallback = buildAsciiFallback(safeFileName);
-  return `attachment; filename="${asciiFallback}"; filename*=UTF-8''${encodeRfc5987Value(safeFileName)}`;
+function buildAttachmentContentDisposition(fileName, options = {}) {
+  return buildContentDisposition(fileName, {
+    ...options,
+    maxCodePoints: PURCHASE_ATTACHMENT_MAX_FILE_NAME_CODE_POINTS,
+  });
 }
 
 module.exports = {
diff --git a/server/src/utils/contentDisposition.js b/server/src/utils/contentDisposition.js
new file mode 100644
index 00000000..46878920
--- /dev/null
+++ b/server/src/utils/contentDisposition.js
@@ -0,0 +1,67 @@
+const DEFAULT_FILE_NAME = "attachment.bin";
+const DEFAULT_MAX_FILE_NAME_CODE_POINTS = 180;
+const ALLOWED_DISPOSITIONS = new Set(["attachment", "inline"]);
+
+function truncateCodePoints(value, maxCodePoints) {
+  const codePoints = Array.from(value);
+  return codePoints.length <= maxCodePoints
+    ? value
+    : codePoints.slice(0, maxCodePoints).join("");
+}
+
+function sanitizeHeaderFileName(fileName, { maxCodePoints = DEFAULT_MAX_FILE_NAME_CODE_POINTS } = {}) {
+  const source = typeof fileName === "string" && fileName.trim()
+    ? fileName.normalize("NFC").trim()
+    : DEFAULT_FILE_NAME;
+  const sanitized = truncateCodePoints(
+    source
+      .replace(/[\\/]/gu, "_")
+      .replace(/[\u0000-\u001f\u007f-\u009f]/gu, "_")
+      .replace(/[\u200b-\u200f\u202a-\u202e\u2060-\u2069\ufeff]/gu, "_")
+      .replace(/"+/gu, "_")
+      .replace(/\s+/gu, " ")
+      .trim(),
+    maxCodePoints,
+  );
+  return sanitized && sanitized !== "." && sanitized !== ".."
+    ? sanitized
+    : DEFAULT_FILE_NAME;
+}
+
+function buildAsciiFallback(fileName) {
+  const lastDotIndex = fileName.lastIndexOf(".");
+  const rawExtension = lastDotIndex > 0 ? fileName.slice(lastDotIndex).toLowerCase() : ".bin";
+  const extension = /^\.[a-z0-9]{1,10}$/u.test(rawExtension) ? rawExtension : ".bin";
+  const rawStem = lastDotIndex > 0 ? fileName.slice(0, lastDotIndex) : fileName;
+  const asciiStem = rawStem
+    .normalize("NFKD")
+    .replace(/[\u0300-\u036f]/gu, "")
+    .replace(/[^a-zA-Z0-9._-]+/gu, "_")
+    .replace(/_+/gu, "_")
+    .replace(/^[._-]+|[._-]+$/gu, "")
+    .slice(0, 100);
+  return `${asciiStem || "attachment"}${extension}`;
+}
+
+function encodeRfc5987Value(value) {
+  return encodeURIComponent(value).replace(/[\u0027\u0028\u0029\u002a]/gu, (character) =>
+    `%${character.charCodeAt(0).toString(16).toUpperCase()}`,
+  );
+}
+
+function buildAttachmentContentDisposition(
+  fileName,
+  { disposition = "attachment", maxCodePoints = DEFAULT_MAX_FILE_NAME_CODE_POINTS } = {},
+) {
+  if (!ALLOWED_DISPOSITIONS.has(disposition)) {
+    throw new TypeError("disposition must be attachment or inline");
+  }
+  const safeFileName = sanitizeHeaderFileName(fileName, { maxCodePoints });
+  const asciiFallback = buildAsciiFallback(safeFileName);
+  return `${disposition}; filename="${asciiFallback}"; filename*=UTF-8''${encodeRfc5987Value(safeFileName)}`;
+}
+
+module.exports = {
+  DEFAULT_MAX_FILE_NAME_CODE_POINTS,
+  buildAttachmentContentDisposition,
+};
diff --git a/server/tests/unit/routes/invoicePool.file.test.js b/server/tests/unit/routes/invoicePool.file.test.js
new file mode 100644
index 00000000..7098d3da
--- /dev/null
+++ b/server/tests/unit/routes/invoicePool.file.test.js
@@ -0,0 +1,80 @@
+const fs = require("node:fs/promises");
+const os = require("node:os");
+const path = require("node:path");
+
+const Fastify = require("fastify");
+
+const { AppError } = require("../../../src/utils/AppError");
+const { registerInvoicePoolReadRoutes } = require("../../../src/routes/invoicePool/read");
+const { signPayload } = require("../../../src/utils/signedUrl");
+
+const INVOICE_ID = "11111111-1111-4111-8111-111111111111";
+const ACTOR_ID = "22222222-2222-4222-8222-222222222222";
+const JWT_SECRET = "synthetic-test-secret";
+
+async function buildApp() {
+  const storageDir = await fs.mkdtemp(path.join(os.tmpdir(), "hyb-oa-invoice-file-"));
+  await fs.writeFile(path.join(storageDir, "invoice.pdf"), "%PDF synthetic\n%%EOF\n");
+
+  const prisma = {
+    invoicePool: {
+      findUnique: vi.fn().mockResolvedValue({
+        storage_path: "invoice.pdf",
+        mime_type: "application/pdf",
+        original_name: "住宿电子普通发票.pdf",
+      }),
+    },
+    auditLog: {
+      create: vi.fn().mockResolvedValue({ id: "audit-1" }),
+    },
+  };
+
+  const app = Fastify();
+  app.decorate("prisma", prisma);
+  app.decorate("config", { jwtSecret: JWT_SECRET, storageDir });
+  app.decorate("authenticate", async () => {});
+  app.decorate("hasPermission", () => false);
+  app.decorate("requirePermission", () => async () => {});
+  app.setErrorHandler((error, request, reply) => {
+    if (error instanceof AppError) {
+      return reply.status(error.statusCode).send({
+        requestId: request.id,
+        error: { code: error.code, message: error.message, details: error.details ?? {} },
+      });
+    }
+    return reply.status(500).send({
+      requestId: request.id,
+      error: { code: "SYS_001", message: "服务器内部错误", details: {} },
+    });
+  });
+  await app.register(registerInvoicePoolReadRoutes, { prefix: "/api" });
+  return { app, prisma, storageDir };
+}
+
+describe("GET /api/invoice-pool/:id/file", () => {
+  it("returns a Chinese PDF name through a safe inline Content-Disposition", async () => {
+    const { app, prisma, storageDir } = await buildApp();
+    const exp = Date.now() + 60_000;
+    const token = signPayload({ invoiceId: INVOICE_ID, actorId: ACTOR_ID, exp }, JWT_SECRET);
+
+    try {
+      const response = await app.inject({
+        method: "GET",
+        url: `/api/invoice-pool/${INVOICE_ID}/file?token=${encodeURIComponent(token)}`,
+      });
+
+      expect(response.statusCode).toBe(200);
+      expect(response.headers["content-type"]).toContain("application/pdf");
+      expect(response.headers["content-disposition"]).toBe(
+        "inline; filename=\"attachment.pdf\"; filename*=UTF-8''%E4%BD%8F%E5%AE%BF%E7%94%B5%E5%AD%90%E6%99%AE%E9%80%9A%E5%8F%91%E7%A5%A8.pdf",
+      );
+      expect(response.headers["content-disposition"]).not.toContain("住宿电子普通发票");
+      expect(prisma.auditLog.create).toHaveBeenCalledWith(
+        expect.objectContaining({ data: expect.objectContaining({ action: "INVOICE_FILE_DOWNLOADED" }) }),
+      );
+    } finally {
+      await app.close();
+      await fs.rm(storageDir, { recursive: true, force: true });
+    }
+  });
+});
diff --git a/server/tests/unit/routes/reimbursements.attachments.test.js b/server/tests/unit/routes/reimbursements.attachments.test.js
index 47975230..088ac158 100644
--- a/server/tests/unit/routes/reimbursements.attachments.test.js
+++ b/server/tests/unit/routes/reimbursements.attachments.test.js
@@ -180,7 +180,7 @@ async function buildApp({ reimbursementStatus = "draft" } = {}) {
 
   await app.register(multipart, {
     attachFieldsToBody: false,
-    limits: { files: 5, fileSize: 5 * 1024 * 1024 },
+    limits: { files: 1, fileSize: 5 * 1024 * 1024 },
   });
   await app.register(reimbursementRoutes, { prefix: "/api" });
 
@@ -188,7 +188,7 @@ async function buildApp({ reimbursementStatus = "draft" } = {}) {
 }
 
 describe("reimbursement attachment routes", () => {
-  it("uploads multiple attachment materials without invoice OCR handling", async () => {
+  it("uploads five attachment materials with the production global one-file baseline", async () => {
     const { app, prisma, tempDir, reimbursementId, createdAttachments } = await buildApp();
 
     try {
@@ -204,6 +204,21 @@ describe("reimbursement attachment routes", () => {
             contentType: "image/png",
             content: "png-content",
           },
+          {
+            filename: "order.jpg",
+            contentType: "image/jpeg",
+            content: "jpg-content",
+          },
+          {
+            filename: "note.webp",
+            contentType: "image/webp",
+            content: "webp-content",
+          },
+          {
+            filename: "extra.pdf",
+            contentType: "application/pdf",
+            content: "%PDF extra",
+          },
         ],
       });
 
@@ -218,7 +233,7 @@ describe("reimbursement attachment routes", () => {
       });
 
       expect(response.statusCode).toBe(200);
-      expect(response.json().data.items).toHaveLength(2);
+      expect(response.json().data.items).toHaveLength(5);
       expect(response.json().data.items[0]).toEqual(
         expect.objectContaining({
           originalName: "contract.pdf",
@@ -230,7 +245,7 @@ describe("reimbursement attachment routes", () => {
           uploadedBy: expect.objectContaining({ name: "测试用户" }),
         }),
       );
-      expect(prisma.reimbursementAttachment.create).toHaveBeenCalledTimes(2);
+      expect(prisma.reimbursementAttachment.create).toHaveBeenCalledTimes(5);
       expect(prisma.auditLog.create).toHaveBeenCalledWith(
         expect.objectContaining({
           data: expect.objectContaining({
@@ -254,6 +269,41 @@ describe("reimbursement attachment routes", () => {
     }
   });
 
+  it("returns a stable validation error when a request contains six files", async () => {
+    const { app, prisma, tempDir, reimbursementId } = await buildApp();
+
+    try {
+      const requestPayload = buildMultipartRequest({
+        files: Array.from({ length: 6 }, (_, index) => ({
+          filename: `attachment-${index + 1}.pdf`,
+          contentType: "application/pdf",
+          content: `%PDF attachment ${index + 1}`,
+        })),
+      });
+
+      const response = await app.inject({
+        method: "POST",
+        url: `/api/reimbursements/${reimbursementId}/attachments`,
+        headers: {
+          authorization: "Bearer test",
+          ...requestPayload.headers,
+        },
+        payload: requestPayload.payload,
+      });
+
+      expect(response.statusCode).toBe(400);
+      expect(response.json().error).toMatchObject({
+        code: "VALID_001",
+        details: { file: "too_many_files", maxFiles: 5 },
+      });
+      expect(prisma.reimbursementAttachment.create).not.toHaveBeenCalled();
+      expect(prisma.auditLog.create).not.toHaveBeenCalled();
+    } finally {
+      await app.close();
+      await fs.rm(tempDir, { recursive: true, force: true });
+    }
+  });
+
   it("rejects attachment upload after reimbursement leaves editable status", async () => {
     const { app, prisma, tempDir, reimbursementId } = await buildApp({ reimbursementStatus: "reviewing" });
 
@@ -322,6 +372,9 @@ describe("reimbursement attachment routes", () => {
 
       expect(downloadResponse.statusCode).toBe(200);
       expect(downloadResponse.headers["content-type"]).toContain("image/png");
+      expect(downloadResponse.headers["content-disposition"]).toBe(
+        "inline; filename=\"payment.png\"; filename*=UTF-8''payment.png",
+      );
       expect(downloadResponse.body).toBe("png-content");
 
       const deleteResponse = await app.inject({
@@ -358,6 +411,39 @@ describe("reimbursement attachment routes", () => {
     }
   });
 
+  it("returns Chinese attachment names through a safe inline Content-Disposition", async () => {
+    const { app, tempDir, reimbursementId, createdAttachments } = await buildApp();
+
+    try {
+      const requestPayload = buildMultipartRequest({
+        files: [{ filename: "payment.pdf", contentType: "application/pdf", content: "%PDF payment" }],
+      });
+      const uploadResponse = await app.inject({
+        method: "POST",
+        url: `/api/reimbursements/${reimbursementId}/attachments`,
+        headers: { authorization: "Bearer test", ...requestPayload.headers },
+        payload: requestPayload.payload,
+      });
+      const attachmentId = uploadResponse.json().data.items[0].id;
+      createdAttachments[0].original_name = "支付截图.pdf";
+
+      const response = await app.inject({
+        method: "GET",
+        url: `/api/reimbursements/${reimbursementId}/attachments/${attachmentId}/file`,
+        headers: { authorization: "Bearer test" },
+      });
+
+      expect(response.statusCode).toBe(200);
+      expect(response.headers["content-disposition"]).toBe(
+        "inline; filename=\"attachment.pdf\"; filename*=UTF-8''%E6%94%AF%E4%BB%98%E6%88%AA%E5%9B%BE.pdf",
+      );
+      expect(response.headers["content-disposition"]).not.toContain("支付截图");
+    } finally {
+      await app.close();
+      await fs.rm(tempDir, { recursive: true, force: true });
+    }
+  });
+
   it("rejects attachment deletion without a meaningful reason before mutation", async () => {
     const { app, prisma, tempDir, reimbursementId } = await buildApp();
 
diff --git a/server/tests/unit/services/purchaseAttachmentPolicy.test.js b/server/tests/unit/services/purchaseAttachmentPolicy.test.js
index 27293692..ea7d78c9 100644
--- a/server/tests/unit/services/purchaseAttachmentPolicy.test.js
+++ b/server/tests/unit/services/purchaseAttachmentPolicy.test.js
@@ -542,4 +542,13 @@ describe("purchase attachment storage and response helpers", () => {
     expect(header).not.toContain("\\quote");
     expect(header).toContain("filename*=UTF-8''");
   });
+
+  it("supports safe inline Content-Disposition without changing the default", () => {
+    const header = buildAttachmentContentDisposition("铁路电子客票.pdf", { disposition: "inline" });
+
+    expect(header).toBe(
+      "inline; filename=\"attachment.pdf\"; filename*=UTF-8''%E9%93%81%E8%B7%AF%E7%94%B5%E5%AD%90%E5%AE%A2%E7%A5%A8.pdf",
+    );
+    expect(() => buildAttachmentContentDisposition("file.pdf", { disposition: "preview" })).toThrow(TypeError);
+  });
 });