feat(client/purchase): 全员优惠月付特殊卡片(¥6/$1,随渠道显价)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

client/lib/l10n/app_text.dart

@@ -587,6 +587,8 @@ abstract class AppText {
   String get orderRebuy;
   String get payMethodNezha;       // 请复制内容后在支付宝内打开 / Copy and open in Alipay
   String get orderStatusExpired;     // 已过期 / Expired
+  String get promoBadge;             // 超值月付 / Best value
+  String get promoOriginalPrice;     // 原价 / Was
 
   // ── 邀请好友(Spec ②占位) ──
   String get inviteEntry;          // 邀请好友得会员 / Invite friends, earn membership

client/lib/l10n/strings_en.dart

@@ -511,4 +511,8 @@ class StringsEn extends AppText {
   String get settingsGroupAbout => 'About';
   @override
   String get orderStatusExpired => 'Expired';
+  @override
+  String get promoBadge => 'Limited-time offer';
+  @override
+  String get promoOriginalPrice => 'Was';
 }

client/lib/l10n/strings_es.dart

@@ -512,4 +512,8 @@ class StringsEs extends AppText {
   String get settingsGroupAbout => 'Acerca de';
   @override
   String get orderStatusExpired => 'Caducado';
+  @override
+  String get promoBadge => 'Oferta especial';
+  @override
+  String get promoOriginalPrice => 'Antes';
 }

client/lib/l10n/strings_ja.dart

@@ -512,4 +512,8 @@ class StringsJa extends AppText {
   String get settingsGroupAbout => 'このアプリについて';
   @override
   String get orderStatusExpired => '期限切れ';
+  @override
+  String get promoBadge => '期間限定オファー';
+  @override
+  String get promoOriginalPrice => '通常価格';
 }

client/lib/l10n/strings_ko.dart

@@ -512,4 +512,8 @@ class StringsKo extends AppText {
   String get settingsGroupAbout => '정보';
   @override
   String get orderStatusExpired => '만료됨';
+  @override
+  String get promoBadge => '한정 특가';
+  @override
+  String get promoOriginalPrice => '정가';
 }

client/lib/l10n/strings_ru.dart

@@ -512,4 +512,8 @@ class StringsRu extends AppText {
   String get settingsGroupAbout => 'О приложении';
   @override
   String get orderStatusExpired => 'Истёк';
+  @override
+  String get promoBadge => 'Спецпредложение';
+  @override
+  String get promoOriginalPrice => 'Было';
 }

client/lib/l10n/strings_zh.dart

@@ -505,4 +505,8 @@ class StringsZh extends AppText {
   String get settingsGroupAbout => '关于';
   @override
   String get orderStatusExpired => '已过期';
+  @override
+  String get promoBadge => '限时优惠';
+  @override
+  String get promoOriginalPrice => '原价';
 }

client/lib/models/payment.dart

@@ -18,6 +18,7 @@ class PayCatalogItem {
     required this.priceMinor,
     required this.currency,
     this.priceUsdtMicro = 0,
+    this.promo = false,
   });
 
   final String sku;
@@ -26,6 +27,7 @@ class PayCatalogItem {
   final int priceMinor;      // CNY 分(展示)
   final String currency;     // CNY
   final int priceUsdtMicro;  // USDT 微元(展示;各币种一口价)
+  final bool promo;          // 全员可见的限时优惠档(如 pro_month_promo)
 
   factory PayCatalogItem.fromJson(Map<String, dynamic> j) => PayCatalogItem(
         sku: j['sku'] as String,
@@ -34,6 +36,7 @@ class PayCatalogItem {
         priceMinor: (j['price_minor'] as num?)?.toInt() ?? 0,
         currency: j['currency'] as String? ?? 'CNY',
         priceUsdtMicro: (j['price_usdt_micro'] as num?)?.toInt() ?? 0,
+        promo: j['promo'] as bool? ?? false,
       );
 
   /// 约当月数(31→1 / 92→3 / 366→12),用于每月折算展示。

client/lib/screens/purchase_page.dart

@@ -13,6 +13,14 @@ import '../widgets/pangolin_icons.dart';
 import '../widgets/plan_card.dart';
 import '../widgets/seg_switch.dart';
 
+/// 手写 firstWhere-or-null(避免仅为一次查找引入 package:collection 依赖)。
+T? _firstWhereOrNull<T>(List<T> items, bool Function(T) test) {
+  for (final it in items) {
+    if (test(it)) return it;
+  }
+  return null;
+}
+
 class PurchaseScreen extends ConsumerStatefulWidget {
   const PurchaseScreen({super.key, required this.t, this.onBack, this.onOrderCreated, this.embedded = false});
 
@@ -62,42 +70,58 @@ class _PurchaseScreenState extends ConsumerState<PurchaseScreen> {
               style: PangolinText.body.copyWith(color: c.fg3)),
         ),
       ),
-      data: (items) => ListView(
+      data: (items) {
-        padding: const EdgeInsets.fromLTRB(20, 14, 20, 24),
+        final promoItem = _firstWhereOrNull(items, (i) => i.promo);
-        children: [
+        final planItems = items.where((i) => !i.promo).toList();
-          // 支付渠道 SegSwitch(默认 USDT;人民币走支付宝)→ 套餐价随之刷新
+        final originalItem = _firstWhereOrNull(items, (i) => i.sku == 'pro_month');
-          Padding(
+        return ListView(
-            padding: const EdgeInsets.only(left: 2, bottom: 8),
+          padding: const EdgeInsets.fromLTRB(20, 14, 20, 24),
-            child: Text(t.payChannel.toUpperCase(),
+          children: [
-                style: PangolinText.caption.copyWith(
+            // 支付渠道 SegSwitch(默认 USDT;人民币走支付宝)→ 套餐价随之刷新
-                    color: c.fg3, fontWeight: FontWeight.w700, letterSpacing: 0.6)),
-          ),
-          SegSwitch(
-            options: [
-              (icon: PangolinIcons.globe, label: t.payChannelUsdt),
-              (icon: PangolinIcons.creditCard, label: t.payChannelCny),
-            ],
-            selectedIndex: _channel == PayChannel.usdt ? 0 : 1,
-            onChanged: (i) => setState(
-                () => _channel = i == 0 ? PayChannel.usdt : PayChannel.cny),
-          ),
-          const SizedBox(height: 18),
-          for (final it in items)
             Padding(
-              padding: EdgeInsets.only(bottom: 14, top: it.sku == 'pro_year' ? 12 : 0),
+              padding: const EdgeInsets.only(left: 2, bottom: 8),
-              child: PlanCard(
+              child: Text(t.payChannel.toUpperCase(),
-                name: _name(it.sku),
+                  style: PangolinText.caption.copyWith(
-                price: it.priceLabel(_channel),
+                      color: c.fg3, fontWeight: FontWeight.w700, letterSpacing: 0.6)),
-                period: '${it.perMonthLabel(_channel)}${t.perMonthSuffix}',
-                features: t.featsPro,
-                ctaLabel: t.buyNow,
-                featured: it.sku == 'pro_year',
-                popularLabel: it.sku == 'pro_year' ? t.mostPopular : null,
-                onPressed: () => _buy(it),
-              ),
             ),
-        ],
+            SegSwitch(
-      ),
+              options: [
+                (icon: PangolinIcons.globe, label: t.payChannelUsdt),
+                (icon: PangolinIcons.creditCard, label: t.payChannelCny),
+              ],
+              selectedIndex: _channel == PayChannel.usdt ? 0 : 1,
+              onChanged: (i) => setState(
+                  () => _channel = i == 0 ? PayChannel.usdt : PayChannel.cny),
+            ),
+            const SizedBox(height: 18),
+            if (promoItem != null)
+              Padding(
+                padding: const EdgeInsets.only(bottom: 14),
+                child: _PromoCard(
+                  t: t,
+                  channel: _channel,
+                  item: promoItem,
+                  originalItem: originalItem,
+                  onPressed: () => _buy(promoItem),
+                ),
+              ),
+            for (final it in planItems)
+              Padding(
+                padding: EdgeInsets.only(bottom: 14, top: it.sku == 'pro_year' ? 12 : 0),
+                child: PlanCard(
+                  name: _name(it.sku),
+                  price: it.priceLabel(_channel),
+                  period: '${it.perMonthLabel(_channel)}${t.perMonthSuffix}',
+                  features: t.featsPro,
+                  ctaLabel: t.buyNow,
+                  featured: it.sku == 'pro_year',
+                  popularLabel: it.sku == 'pro_year' ? t.mostPopular : null,
+                  onPressed: () => _buy(it),
+                ),
+              ),
+          ],
+        );
+      },
     );
 
     if (widget.embedded) return body;
@@ -122,3 +146,104 @@ class _PurchaseScreenState extends ConsumerState<PurchaseScreen> {
     );
   }
 }
+
+/// _PromoCard — 全员优惠月付特殊卡片(横幅式,视觉上与普通 PlanCard 拉开层次)。
+/// 徽章 + 大号现价(随渠道 ¥/$ 联动)+ 可选原价划线(以 pro_month 为参照)。
+class _PromoCard extends StatelessWidget {
+  const _PromoCard({
+    required this.t,
+    required this.channel,
+    required this.item,
+    required this.originalItem,
+    required this.onPressed,
+  });
+
+  final AppText t;
+  final PayChannel channel;
+  final PayCatalogItem item;
+  final PayCatalogItem? originalItem;
+  final VoidCallback onPressed;
+
+  @override
+  Widget build(BuildContext context) {
+    final originalLabel = originalItem?.priceLabel(channel);
+
+    return Container(
+      padding: const EdgeInsets.fromLTRB(18, 16, 18, 16),
+      decoration: BoxDecoration(
+        gradient: const LinearGradient(
+          begin: Alignment.topLeft,
+          end: Alignment.bottomRight,
+          colors: [PangolinColors.clay500, PangolinColors.clay700],
+        ),
+        borderRadius: BorderRadius.circular(PangolinRadius.xl),
+        boxShadow: PangolinShadow.md,
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Container(
+            padding: const EdgeInsets.symmetric(horizontal: 9, vertical: 4),
+            decoration: BoxDecoration(
+              color: PangolinColors.white.withValues(alpha: 0.22),
+              borderRadius: BorderRadius.circular(PangolinRadius.full),
+            ),
+            child: Row(mainAxisSize: MainAxisSize.min, children: [
+              Icon(PangolinIcons.zap, size: 13, color: PangolinColors.white),
+              const SizedBox(width: 4),
+              Text(t.promoBadge,
+                  style: PangolinText.caption.copyWith(
+                      color: PangolinColors.white, fontWeight: FontWeight.w700, fontSize: 11)),
+            ]),
+          ),
+          const SizedBox(height: 12),
+          Text(t.proMonthly,
+              style: PangolinText.sm.copyWith(
+                  color: PangolinColors.white.withValues(alpha: 0.85), fontWeight: FontWeight.w600)),
+          const SizedBox(height: 6),
+          Row(
+            crossAxisAlignment: CrossAxisAlignment.baseline,
+            textBaseline: TextBaseline.alphabetic,
+            children: [
+              Text(item.priceLabel(channel),
+                  style: PangolinText.display.copyWith(color: PangolinColors.white, fontSize: 30)),
+              Text(t.perMonthSuffix,
+                  style: PangolinText.caption.copyWith(
+                      color: PangolinColors.white.withValues(alpha: 0.85), fontSize: 13)),
+              if (originalLabel != null) ...[
+                const SizedBox(width: 8),
+                Text(originalLabel,
+                    style: PangolinText.sm.copyWith(
+                      color: PangolinColors.white.withValues(alpha: 0.62),
+                      fontSize: 14,
+                      decoration: TextDecoration.lineThrough,
+                    )),
+              ],
+            ],
+          ),
+          const SizedBox(height: 16),
+          SizedBox(
+            width: double.infinity,
+            child: Material(
+              color: PangolinColors.white,
+              shape: const StadiumBorder(),
+              clipBehavior: Clip.antiAlias,
+              child: InkWell(
+                onTap: onPressed,
+                child: Padding(
+                  padding: const EdgeInsets.symmetric(vertical: 12),
+                  child: Center(
+                    child: Text(t.buyNow,
+                        style: PangolinText.sm.copyWith(
+                            fontWeight: FontWeight.w700, fontSize: 14, color: PangolinColors.clay700)),
+                  ),
+                ),
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}

client/test/widget/payment_pages_test.dart

@@ -18,6 +18,13 @@ const _items = [
   PayCatalogItem(sku: 'pro_year', plan: 'pro', days: 366, priceMinor: 19999, currency: 'CNY', priceUsdtMicro: 34990000),
 ];
 
+const _itemsWithPromo = [
+  PayCatalogItem(
+      sku: 'pro_month_promo', plan: 'pro', days: 31, priceMinor: 600, currency: 'CNY',
+      priceUsdtMicro: 1000000, promo: true),
+  ..._items,
+];
+
 /// 轮询生命周期测试专用假 API:记 orderStatus / cancel 调用次数,其余按最小实现返回。
 class _PollingFakePaymentApi implements PaymentApi {
   int statusCalls = 0;
@@ -80,6 +87,29 @@ void main() {
     expect(find.text('¥199.99'), findsOneWidget);
   });
 
+  testWidgets('购买页:全员优惠月付特殊卡片(随渠道显价 + 原价划线)', (tester) async {
+    tester.view.physicalSize = const Size(800, 2400);
+    tester.view.devicePixelRatio = 1.0;
+    addTearDown(tester.view.reset);
+    await tester.pumpWidget(wrapThemed(
+      PurchaseScreen(t: t, embedded: true),
+      overrides: [payCatalogProvider.overrideWith((ref) async => _itemsWithPromo)],
+    ));
+    await tester.pumpAndSettle();
+    // 普通 3 档照旧渲染 + 1 张特殊卡片(非 PlanCard)。
+    expect(find.byType(PlanCard), findsNWidgets(3));
+    expect(find.text(t.promoBadge), findsOneWidget);
+    // 默认 USDT → 现价 \$1.00;原价(pro_month)\$4.99 同时出现在划线原价 + 下方普通
+    // pro_month PlanCard(两处同值,断言 2 处)。
+    expect(find.text('\$1.00'), findsOneWidget);
+    expect(find.text('\$4.99'), findsNWidgets(2));
+    // 切到人民币 → 现价 ¥6.00;原价 ¥29.99 同理 2 处。
+    await tester.tap(find.text(t.payChannelCny));
+    await tester.pumpAndSettle();
+    expect(find.text('¥6.00'), findsOneWidget);
+    expect(find.text('¥29.99'), findsNWidgets(2));
+  });
+
   testWidgets('支付页 crypto_address:地址/金额/复制,金额用 mono', (tester) async {
     final flow = PaymentFlowState(
       phase: PaymentPhase.awaitingPayment,