feat: 选票自动生成报销明细并支持集中分类（08-29-reimbursement-expense-policy-invoice-guard）

server/src/services/invoiceExpenseClassification.js

@@ -0,0 +1,30 @@
+const { mapInvoiceDocumentMeta } = require("./invoiceDocumentMeta");
+const { buildBusinessValidationError } = require("../utils/businessValidationError");
+
+function suggestInvoiceExpenseType(invoice, expenseTypes) {
+  const { documentCategory } = mapInvoiceDocumentMeta(invoice);
+  if (documentCategory !== "electronic_train_ticket") return null;
+
+  const expenseType = expenseTypes.find((type) => type.enabled === true && type.code === "travel_train");
+  if (!expenseType) return null;
+
+  return { expenseTypeId: expenseType.id, source: "document_category" };
+}
+
+function ensureClassifiedReimbursementItems(items) {
+  const itemIds = items
+    .filter((item) => !item.expense_type || item.expense_type.enabled === false)
+    .map((item) => item.id);
+  if (itemIds.length) {
+    throw buildBusinessValidationError("reimbursement.items_expense_type_required", { itemIds }, 400);
+  }
+}
+
+function ensureReimbursementItemDescriptions(items) {
+  const itemIds = items.filter((item) => !item.description?.trim()).map((item) => item.id);
+  if (itemIds.length) {
+    throw buildBusinessValidationError("reimbursement.items_description_required", { itemIds }, 400);
+  }
+}
+
+module.exports = { suggestInvoiceExpenseType, ensureClassifiedReimbursementItems, ensureReimbursementItemDescriptions };