feat(client): 入库/出库搜索框支持酒名，并对搜索限流

- 搜索框 hint 改为「单号/往来单位/酒名」
- setKeyword 加去重+350ms 防抖：同词不重查、连发回车/狂点合并取最后一次，
  避免酒名模糊查询（单次约 55ms 明细扫描）被刷
- Timer 在 provider dispose 时取消

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/lib/screens/stock_in/stock_in_list_screen.dart

@@ -366,7 +366,7 @@ class _StockInListScreenState extends ConsumerState<StockInListScreen> {
         final searchField = TextField(
           controller: _searchCtrl,
           decoration: InputDecoration(
-            hintText: '单号/往来单位，回车搜索',
+            hintText: '单号/往来单位/酒名，回车搜索',
             prefixIcon: const Icon(Icons.search, size: 16),
             hintStyle: const TextStyle(fontSize: 12),
             suffixIcon: IconButton(

client/lib/screens/stock_out/stock_out_list_screen.dart

@@ -378,7 +378,7 @@ class _StockOutListScreenState extends ConsumerState<StockOutListScreen> {
         final searchField = TextField(
           controller: _searchCtrl,
           decoration: InputDecoration(
-            hintText: '单号/往来单位，回车搜索',
+            hintText: '单号/往来单位/酒名，回车搜索',
             prefixIcon: const Icon(Icons.search, size: 16),
             hintStyle: const TextStyle(fontSize: 12),
             suffixIcon: IconButton(