fix(order-service): 修复包含 Emoji 和孤立代理字符的订单在 PostgreSQL jsonb 下报错导致死循环重试进单的问题

1. 在 utils/json.ts 新增 sanitizeWellFormedUnicode、deepSanitizeUnicode 和 safeJsonStringify，自动清理空字节 (\0) 并将畸变孤立 UTF-16 代理字符 (Lone Surrogates) 安全转换为规范字符，杜绝 PostgreSQL jsonb 解析错误；
2. 拼多多订单映射器与通用进单服务 (order-service) 全面接入 Unicode 深度清洗与安全序列化，确保买家昵称/留言中的各类特殊 Emoji 和生僻字符平滑落库；
3. 数据库仓储层 (order-repo / order-item-repo) 针对 raw_payload_json、spec_json、item_snapshot_json 等 jsonb 字段增加兜底安全序列化保护；
4. 补充 utils/json.test.ts 与 pdd-order-mapper.test.ts 单元测试，覆盖畸变字符与空字节场景。

apps/backend/src/services/order/order-service.ts

@@ -19,6 +19,7 @@ import {
 import { nowIso } from '../../utils/time.js'
 import { logDebug, logInfo, logIntegration, logWarn } from '../../utils/logger.js'
 import { createHttpError } from '../../utils/http.js'
+import { safeJsonStringify, sanitizeWellFormedUnicode } from '../../utils/json.js'
 import type { OrderItemRow, OrderRow, TaskRow } from '../../types/repository/rows.js'
 
 type SourceOrderItem = {
@@ -138,12 +139,12 @@ export async function upsertOrderFromSource(
       platformOrderId: event.platformOrderId,
       orderStatus: event.orderStatus,
       payStatus: event.payStatus,
-      buyerId: event.buyerId,
-      buyerName: event.buyerName,
-      receiverContact: event.receiverContact,
+      buyerId: sanitizeWellFormedUnicode(event.buyerId),
+      buyerName: sanitizeWellFormedUnicode(event.buyerName),
+      receiverContact: sanitizeWellFormedUnicode(event.receiverContact),
       totalAmount: event.totalAmount,
       currency: event.currency,
-      rawPayloadJson: JSON.stringify(event.rawPayload),
+      rawPayloadJson: safeJsonStringify(event.rawPayload),
       ...(event.paidAt !== undefined ? { paidAt: event.paidAt } : {}),
     }
     const mergedPayload = mergeSourceOrderState(existing, basePayload)
@@ -172,11 +173,11 @@ export async function upsertOrderFromSource(
       executor,
       order.id,
       resolvedFulfillmentItems.map((item) => ({
-        skuCode: item.skuCode,
-        skuName: item.skuName,
+        skuCode: sanitizeWellFormedUnicode(item.skuCode),
+        skuName: sanitizeWellFormedUnicode(item.skuName),
         quantity: item.quantity,
-        specJson: JSON.stringify(item.spec || {}),
-        itemSnapshotJson: JSON.stringify(item.snapshot || item.spec || {}),
+        specJson: safeJsonStringify(item.spec || {}),
+        itemSnapshotJson: safeJsonStringify(item.snapshot || item.spec || {}),
         createdAt: now,
         updatedAt: now,
       })),