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/lib/models/finance.dart

@@ -40,6 +40,17 @@ class FinanceRecord {
     }
   }
 
+  /// 单据抬头（近期单据列表用）：收付款显示类型，应收/应付回溯到来源单据
+  String get docTitle {
+    final ref = switch (refType) {
+      'stock_in' => '入库单',
+      'stock_out' => '出库单',
+      _ => null,
+    };
+    if (ref != null) return ref;
+    return typeLabel;
+  }
+
   factory FinanceRecord.fromJson(Map<String, dynamic> json) => FinanceRecord(
         id: (json['id'] as num).toInt(),
         type: json['type'] as String,
@@ -47,13 +58,57 @@ class FinanceRecord {
         balance: (json['balance'] as num).toDouble(),
         status: json['status'] as String? ?? 'open',
         refType: json['ref_type'] as String?,
-        refId:
-            json['ref_id'] != null ? (json['ref_id'] as num).toInt() : null,
+        refId: json['ref_id'] != null ? (json['ref_id'] as num).toInt() : null,
         partnerName:
             (json['partner'] as Map<String, dynamic>?)?['name'] as String?,
-        partnerId:
-            json['partner_id'] != null ? (json['partner_id'] as num).toInt() : null,
+        partnerId: json['partner_id'] != null
+            ? (json['partner_id'] as num).toInt()
+            : null,
         recordDate: json['record_date'] as String?,
         remark: json['remark'] as String?,
       );
 }
+
+/// GET /finance/summary 行：按往来单位分组的未结清应收/应付聚合
+class PartnerFinanceSummary {
+  final int? partnerId;
+  final String partnerName;
+  final String type; // payable | receivable
+  final int recordCount;
+  final double totalAmount;
+
+  const PartnerFinanceSummary({
+    this.partnerId,
+    this.partnerName = '',
+    required this.type,
+    this.recordCount = 0,
+    required this.totalAmount,
+  });
+
+  factory PartnerFinanceSummary.fromJson(Map<String, dynamic> json) =>
+      PartnerFinanceSummary(
+        partnerId: json['partner_id'] != null
+            ? (json['partner_id'] as num).toInt()
+            : null,
+        partnerName: json['partner_name'] as String? ?? '',
+        type: json['type'] as String,
+        recordCount: (json['record_count'] as num?)?.toInt() ?? 0,
+        totalAmount: (json['total_amount'] as num?)?.toDouble() ?? 0,
+      );
+}
+
+/// GET /finance/trend 点：月度收支（in=销售额、out=采购额，单位元）。
+class TrendPoint {
+  final String month; // "2026-01"
+  final double inAmount;
+  final double outAmount;
+
+  const TrendPoint(
+      {required this.month, required this.inAmount, required this.outAmount});
+
+  factory TrendPoint.fromJson(Map<String, dynamic> json) => TrendPoint(
+        month: json['month'] as String? ?? '',
+        inAmount: (json['in'] as num?)?.toDouble() ?? 0,
+        outAmount: (json['out'] as num?)?.toDouble() ?? 0,
+      );
+}