feat(client): 登录/注册页照原型重建，ds 真相源组件族统一全部屏

- 登录/注册（login.html/register.html 1:1）：两栏卡片+品牌渐变面板+主题小衣服
  pill（onSurface 变体）+记住我（记录并预填最近账号）+原型式 toast 校验；
  登录 fidelity 1.4–2.1% 三主题全绿；注册暂不入闸（少 门店编号/兑换券 字段，
  已记 CONTRACT，screens.mjs 留存根）
- ds 原子补齐：DsToast（.toast 单例）/DsCheck（.check/.agree）/DsButton lg 档/
  DsSelect 替换全部旧 DropdownButton/DsField label 在上/DsInput 后缀与密码形态
- 全屏统一：对话框按钮全 DsButton、盒式输入主题钉死（visualDensity.standard、
  h38、InputDecorationTheme 渗漏修复）、图标全 lucide、JetBrains Mono 三端同源、
  BrandMark 真相源 logo、只读模式写操作全量守卫（WriteGuard+DsToast）
- 出入库列表：版式对齐原型（卡片对齐+搜索框居中）、KPI 近30天滚动、结清后
  失效财务应收应付表；商品编辑抽屉介绍库改搜索下拉、图片双击全屏预览
- 删除旧 UI 死代码：DataTableCard/FormDialog/PageScaffold/SearchChip/
  SelectProductDialog/tabStateProvider
- golden/fidelity：stock-in/out 补注册（9%）、login 入册（8%）、goldens 全量重打；
  修复 pubspec flutter_web_plugins 非法声明（CI pub get 阻断）

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JJ1g8XV1YhhmHRzhwWEW7o

client/test/grid_combo_cell_pick_test.dart

@@ -0,0 +1,63 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:jiu_client/core/theme/themes.dart';
+import 'package:jiu_client/widgets/ds/grid_combo_cell.dart';
+import 'package:jiu_client/widgets/searchable_option_field.dart'
+    show OptionItem;
+
+void main() {
+  testWidgets('popupSearch grid combo: tapping a row fills selection',
+      (tester) async {
+    int? picked;
+    int selectedId = 0;
+    final fn = FocusNode();
+    final opts = [
+      OptionItem(id: 1, name: '茅台飞天'),
+      OptionItem(id: 2, name: '五粮液'),
+    ];
+
+    await tester.pumpWidget(MaterialApp(
+      theme: buildTheme('a'),
+      home: Scaffold(
+        body: StatefulBuilder(builder: (context, setState) {
+          return Center(
+            child: SizedBox(
+              width: 240,
+              child: GridComboCell(
+                focusNode: fn,
+                cell: true,
+                popupSearch: true,
+                hint: '选择商品名称',
+                options: opts,
+                selectedId: selectedId == 0 ? null : selectedId,
+                onChanged: (v) => setState(() {
+                  picked = v;
+                  selectedId = v ?? 0;
+                }),
+              ),
+            ),
+          );
+        }),
+      ),
+    ));
+
+    fn.requestFocus();
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 50));
+
+    expect(find.text('五粮液'), findsOneWidget);
+
+    // Realistic pointer: down, drain microtasks/frames (focus-loss handlers run
+    // here), THEN up — mirrors real input where the search field defocuses on
+    // pointer-down before the row's onTap fires on pointer-up.
+    final g = await tester.startGesture(tester.getCenter(find.text('五粮液')));
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 50));
+    await g.up();
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 50));
+
+    expect(picked, 2,
+        reason: 'onChanged should fire with id=2 after tapping row');
+  });
+}