fix(erp-export): strict seit format, DB clock for settle window, movement index, one scope per key

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

ApiCore-Backend/prisma/migrations/20261013130000_batch_movement_created_at_index/migration.sql

@@ -0,0 +1,3 @@
+-- ERP-Export /bewegungen sortiert und blättert nach (createdAt, id).
+-- CreateIndex
+CREATE INDEX "BatchMovement_createdAt_id_idx" ON "BatchMovement"("createdAt", "id");

ApiCore-Backend/prisma/schema.prisma

@@ -1210,6 +1210,8 @@ model BatchMovement {
   @@index([productionBatchId])
   @@index([rawMaterialLotId])
   @@index([shopRequestId])
+  // ERP-Export /bewegungen: sortiert und blättert nach (createdAt, id).
+  @@index([createdAt, id])
 }
 
 enum ShopStockRequestKind {