修复：恢复 PostgreSQL 集成测试并规范工单搜索条件

apps/backend/src/repositories/worker-platform/work-order-query-repo.ts

@@ -690,6 +690,7 @@ export function buildWorkOrderWhere({
   const filters: string[] = []
   const params: unknown[] = []
   const joins: string[] = []
+  const normalizedKeyword = String(keyword || '').trim()
   if (createdFrom) {
     params.push(createdFrom)
     filters.push(
@@ -808,8 +809,8 @@ export function buildWorkOrderWhere({
     params.push(workOrderId)
     filters.push(`wo.id = $${params.length}`)
   }
-  if (keyword) {
-    params.push(`%${keyword}%`)
+  if (normalizedKeyword) {
+    params.push(`%${normalizedKeyword}%`)
     filters.push(`${workOrderSearchExpression()} LIKE LOWER($${params.length})`)
   }
   if (workerId) {