feat: RIIN 商品拉取改用 goods/list 批量接口(200/批串行)替换逐单 order/goods

- api/riin/client.py: 新增 get_order_goods_batch(distribution/order/goods/list)
- flows/shared/clients.py: fetch_goods_concurrent → fetch_goods_for_orders,
  批量 200/批、串行、批间 2s,批级重试;移除逐单全局限速(340~500ms)机制
- flows/riin/_pipeline.py: 适配新批量拉取
- flows/shared/db.py: 存在性预查 unnest cast timestamp[] → timestamptz[]
  (入参为带时区偏移的 tz-aware datetime,timestamptz 才能稳定匹配)

背景:旧逐单接口高频被软限流(成功返回空 data),10-28 起日均缺口 13~33%;
批量接口调用量从日均 ~1 万次降到 ~50 次,已实测回补 7689 单/9717 条商品全量成功。

flows/shared/__init__.py

@@ -5,7 +5,7 @@ from flows.shared.artifacts import build_stats_rows, emit_sync_summary, emit_ver
 from flows.shared.clients import (
     create_riin_client,
     create_sds_client,
-    fetch_goods_concurrent,
+    fetch_goods_for_orders,
     fetch_riin_all_pages,
     fetch_sds_all_pages,
     floor_to_hour,
@@ -23,7 +23,7 @@ __all__ = [
     "clients", "db", "mappers", "SyncDB",
     "OrderUpsertInput", "GoodsUpsertInput",
     "create_riin_client", "create_sds_client",
-    "fetch_riin_all_pages", "fetch_sds_all_pages", "fetch_goods_concurrent",
+    "fetch_riin_all_pages", "fetch_sds_all_pages", "fetch_goods_for_orders",
     "get_channel_type_map", "refresh_channel_type_map", "resolve_courier_source",
     "format_date", "start_of_day", "floor_to_hour",
     "build_stats_rows", "emit_sync_summary", "emit_verify_report",