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/user_menu_width_test.dart

@@ -21,8 +21,14 @@ class _FakeAuth extends AuthNotifier {
   _FakeAuth() {
     state = const AuthState(
       user: AuthUser(
-          accessToken: 't', refreshToken: 'r', id: 1, username: 'wang',
-          realName: '王经理', shopNo: 'DSJH-001', shopId: 1, role: 'admin'),
+          accessToken: 't',
+          refreshToken: 'r',
+          id: 1,
+          username: 'wang',
+          realName: '王经理',
+          shopNo: 'DSJH-001',
+          shopId: 1,
+          role: 'admin'),
     );
   }
 }
@@ -38,8 +44,12 @@ class _FakeLicense extends LicenseNotifier {
 }
 
 const _shop = ShopInfo(
-    id: 1, code: 'DSJH-001', name: '鼎晟酒行',
-    address: '浙江省杭州市', phone: '0571-88886666', managerName: '王经理');
+    id: 1,
+    code: 'DSJH-001',
+    name: '鼎晟酒行',
+    address: '浙江省杭州市',
+    phone: '0571-88886666',
+    managerName: '王经理');
 
 GoRouter _router() => GoRouter(
       initialLocation: '/inventory',
@@ -48,8 +58,15 @@ GoRouter _router() => GoRouter(
           builder: (ctx, state, shell) => AppShell(navigationShell: shell),
           branches: [
             for (final p in const [
-              '/stock-in', '/stock-out', '/inventory', '/finance',
-              '/partners', '/products', '/devices', '/settings', '/about'
+              '/stock-in',
+              '/stock-out',
+              '/inventory',
+              '/finance',
+              '/partners',
+              '/products',
+              '/devices',
+              '/settings',
+              '/about'
             ])
               StatefulShellBranch(routes: [
                 GoRoute(path: p, builder: (_, __) => const SizedBox.expand()),