fix(firstleg): expose container documents and aggregate departure gates

firstleg/src/main/resources/openapi/loading-lists-v1.yaml

@@ -99,6 +99,29 @@ paths:
         content: {application/json: {schema: {$ref: '#/components/schemas/DocumentAttachRequest'}}}
       responses:
         '200': {$ref: '#/components/responses/BusinessDocumentResponse'}
+  /api/platform/v1/first-leg/loading-lists/{planId}/customs/document/{fileId}/download:
+    get:
+      summary: 下载装柜清单出口报关附件
+      description: 完成态仍可下载。服务端校验 planId、warehouseId、当前 CUSTOMS_DECLARATION 的 fileId，以及 File 元数据 tenantId=0、businessType=LOADING_CUSTOMS_DECLARATION、businessId=planId；错误 fileId 或归属返回 A0404。响应使用 attachment 文件名并禁止缓存。
+      x-permission: platform:firstleg:loading-list:list
+      parameters:
+        - {$ref: '#/components/parameters/PlanId'}
+        - {$ref: '#/components/parameters/WarehouseId'}
+        - name: fileId
+          in: path
+          required: true
+          description: File 服务长整型文件 ID
+          schema: {$ref: '#/components/schemas/LongId'}
+      responses:
+        '200':
+          description: 报关附件二进制内容；包含 Content-Disposition，Cache-Control 为 no-store
+          headers:
+            Content-Disposition: {schema: {type: string}}
+            Cache-Control: {schema: {type: string, example: no-store}}
+          content:
+            application/octet-stream:
+              schema: {type: string, format: binary}
+        '404': {description: 装柜计划、仓库、当前附件或 File 归属不匹配}
   /api/platform/v1/first-leg/loading-lists/{planId}/customs/document/upload:
     post:
       summary: 直接选择文件上传或替换装柜清单出口报关文档