refactor(client): SubScaffold 六合一(视觉零变化)+ tablet 注释订正 + 平板通知铃入口(#20)

client/lib/screens/invite_page.dart

@@ -16,6 +16,7 @@ import '../widgets/page_body.dart';
 import '../widgets/pangolin_button.dart';
 import '../widgets/pangolin_icons.dart';
 import '../widgets/pangolin_toast.dart';
+import '../widgets/sub_scaffold.dart';
 
 class InviteScreen extends ConsumerWidget {
   const InviteScreen({super.key, required this.t, this.onBack, this.embedded = false});
@@ -59,7 +60,6 @@ class InviteScreen extends ConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
-    final c = context.pangolin;
     final inviteAsync = ref.watch(inviteProvider);
 
     Widget body = PageBody(child: inviteAsync.when(
@@ -70,24 +70,11 @@ class InviteScreen extends ConsumerWidget {
           : _InviteContent(t: t, info: info, onCopy: _copy, onVerifyAndClaim: (ctx) => _verifyAndClaim(ctx, ref)),
     ));
 
-    if (embedded) return body;
-    return Scaffold(
-      backgroundColor: c.bg,
-      body: SafeArea(
-        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-          Padding(
-            padding: const EdgeInsets.fromLTRB(8, 6, 16, 10),
-            child: Row(children: [
-              IconButton(
-                onPressed: onBack ?? () => Navigator.of(context).maybePop(),
-                icon: Icon(PangolinIcons.arrowLeft, size: 22, color: c.fg1),
-              ),
-              Text(t.inviteTitle, style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
-            ]),
-          ),
-          Expanded(child: body),
-        ]),
-      ),
+    return SubScaffold(
+      title: t.inviteTitle,
+      onBack: onBack,
+      embedded: embedded,
+      child: body,
     );
   }
 }

client/lib/screens/notifications_page.dart

@@ -7,9 +7,9 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import '../l10n/app_text.dart';
 import '../pangolin_theme.dart';
-import '../widgets/page_body.dart';
 import '../widgets/pangolin_icons.dart';
 import '../widgets/status_pill.dart';
+import '../widgets/sub_scaffold.dart';
 
 typedef _Notice = ({
   IconData icon,
@@ -137,24 +137,12 @@ class NotificationsScreen extends ConsumerWidget {
           ],
         );
 
-    if (embedded) return PageBody(child: content());
-    return Scaffold(
-      backgroundColor: c.bg,
-      body: SafeArea(
-        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-          Padding(
-            padding: const EdgeInsets.fromLTRB(8, 6, 16, 10),
-            child: Row(children: [
-              IconButton(
-                onPressed: onBack ?? () => Navigator.of(context).maybePop(),
-                icon: Icon(PangolinIcons.arrowLeft, size: 22, color: c.fg1),
-              ),
-              Text(t.notifTitle, style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
-            ]),
-          ),
-          Expanded(child: PageBody(child: content())),
-        ]),
-      ),
+    return SubScaffold(
+      title: t.notifTitle,
+      onBack: onBack,
+      embedded: embedded,
+      wrapPageBody: true,
+      child: content(),
     );
   }
 }

client/lib/screens/orders_page.dart

@@ -14,6 +14,7 @@ import '../pangolin_theme.dart';
 import '../state/navigation_provider.dart';
 import '../state/orders_provider.dart';
 import '../widgets/page_body.dart';
+import '../widgets/sub_scaffold.dart';
 import '../widgets/pangolin_button.dart';
 import '../widgets/pangolin_icons.dart';
 import '../widgets/status_pill.dart';
@@ -58,38 +59,6 @@ String _fmtDateTime(DateTime d) {
   return '${l.year}-${two(l.month)}-${two(l.day)} ${two(l.hour)}:${two(l.minute)}';
 }
 
-/// 带返回栏的子页骨架(embedded=true 只返回内容,返回/标题由外层 shell 顶栏提供)。
-class _SubScaffold extends StatelessWidget {
-  const _SubScaffold({required this.title, required this.child, this.onBack, this.embedded = false});
-  final String title;
-  final Widget child;
-  final VoidCallback? onBack;
-  final bool embedded;
-  @override
-  Widget build(BuildContext context) {
-    final c = context.pangolin;
-    if (embedded) return PageBody(child: child);
-    return Scaffold(
-      backgroundColor: c.bg,
-      body: SafeArea(
-        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-          Padding(
-            padding: const EdgeInsets.fromLTRB(8, 6, 16, 10),
-            child: Row(children: [
-              IconButton(
-                onPressed: onBack ?? () => Navigator.of(context).maybePop(),
-                icon: Icon(PangolinIcons.arrowLeft, size: 22, color: c.fg1),
-              ),
-              Text(title, style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
-            ]),
-          ),
-          Expanded(child: PageBody(child: child)),
-        ]),
-      ),
-    );
-  }
-}
-
 /// 订单页入口:内部在「列表」与「详情」两屏间切换(与原型单帧同构)。
 class OrdersScreen extends ConsumerStatefulWidget {
   const OrdersScreen({super.key, required this.t, this.onBack, this.embedded = false});
@@ -196,7 +165,7 @@ class _OrderListView extends ConsumerWidget {
           ]),
         );
 
-    return _SubScaffold(title: t.ordersTitle, onBack: onBack, embedded: embedded, child: content());
+    return SubScaffold(title: t.ordersTitle, onBack: onBack, embedded: embedded, wrapPageBody: true, child: content());
   }
 
   Widget _row(BuildContext context, PangolinScheme c, PayOrderSummary o, bool divider) {
@@ -289,7 +258,7 @@ class _OrderDetailView extends ConsumerWidget {
     final expiresAt = detailAsync.valueOrNull?.expiresAt;
     final pill = _statusPill(t, o.status);
 
-    // 内容区(mobile 套 _SubScaffold;desktop embedded 前置一条返回条回到列表)。
+    // 内容区(mobile 套 SubScaffold;desktop embedded 前置一条返回条回到列表)。
     Widget summaryCard() => Container(
           width: double.infinity,
           decoration: BoxDecoration(
@@ -376,7 +345,7 @@ class _OrderDetailView extends ConsumerWidget {
         Expanded(child: PageBody(child: body())),
       ]);
     }
-    return _SubScaffold(title: t.orderDetailTitle, onBack: onBack, child: body());
+    return SubScaffold(title: t.orderDetailTitle, onBack: onBack, wrapPageBody: true, child: body());
   }
 
   Widget _kv(PangolinScheme c, String label, String value, {VoidCallback? onCopy}) {

client/lib/screens/payment_page.dart

@@ -15,6 +15,7 @@ import '../state/payment_provider.dart';
 import '../widgets/pangolin_button.dart';
 import '../widgets/pangolin_icons.dart';
 import '../widgets/pangolin_toast.dart';
+import '../widgets/sub_scaffold.dart';
 
 class PaymentScreen extends ConsumerStatefulWidget {
   const PaymentScreen({super.key, required this.t, this.onBack, this.onDone, this.embedded = false});
@@ -311,25 +312,11 @@ class _PaymentScreenState extends ConsumerState<PaymentScreen> {
               style: PangolinText.body.copyWith(color: c.fg3))),
     };
 
-    if (embedded) return body;
-    return Scaffold(
-      backgroundColor: c.bg,
-      body: SafeArea(
-        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-          Padding(
-            padding: const EdgeInsets.fromLTRB(8, 6, 16, 10),
-            child: Row(children: [
-              IconButton(
-                onPressed: onBack ?? () => Navigator.of(context).maybePop(),
-                icon: Icon(PangolinIcons.arrowLeft, size: 22, color: c.fg1),
-              ),
-              Text(t.paymentTitle,
-                  style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
-            ]),
-          ),
-          Expanded(child: body),
-        ]),
-      ),
+    return SubScaffold(
+      title: t.paymentTitle,
+      onBack: onBack,
+      embedded: embedded,
+      child: body,
     );
   }
 }

client/lib/screens/purchase_page.dart

@@ -11,6 +11,7 @@ import '../pangolin_theme.dart';
 import '../state/payment_provider.dart';
 import '../widgets/page_body.dart';
 import '../widgets/pangolin_icons.dart';
+import '../widgets/sub_scaffold.dart';
 import '../widgets/pangolin_toast.dart';
 import '../widgets/plan_card.dart';
 import '../widgets/seg_switch.dart';
@@ -133,25 +134,11 @@ class _PurchaseScreenState extends ConsumerState<PurchaseScreen> {
       },
     ));
 
-    if (widget.embedded) return body;
-    return Scaffold(
-      backgroundColor: c.bg,
-      body: SafeArea(
-        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-          Padding(
-            padding: const EdgeInsets.fromLTRB(8, 6, 16, 10),
-            child: Row(children: [
-              IconButton(
-                onPressed: widget.onBack ?? () => Navigator.of(context).maybePop(),
-                icon: Icon(PangolinIcons.arrowLeft, size: 22, color: c.fg1),
-              ),
-              Text(t.purchaseTitle,
-                  style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
-            ]),
-          ),
-          Expanded(child: body),
-        ]),
-      ),
+    return SubScaffold(
+      title: t.purchaseTitle,
+      onBack: widget.onBack,
+      embedded: widget.embedded,
+      child: body,
     );
   }
 }

client/lib/shell/tablet_shell.dart

@@ -10,6 +10,7 @@ import '../screens/account_page.dart';
 import '../screens/connect_page.dart';
 import '../screens/contact_page.dart';
 import '../screens/nodes_page.dart';
+import '../screens/notifications_page.dart';
 import '../screens/settings_page.dart';
 import '../screens/stats_page.dart';
 import '../state/app_providers.dart';
@@ -27,7 +28,7 @@ class TabletShell extends ConsumerWidget {
     final t = ref.watch(appTextProvider);
     final view = ref.watch(navViewProvider);
 
-    // 「我的」移到侧栏顶部品牌按钮(见 NavSidebar);设置/联系我们对齐桌面侧栏。
+    // 「我的」经侧栏底部 PlanBadgeCard 进入(见 NavSidebar;品牌块本身不可点);设置/联系我们对齐桌面侧栏。
     final items = <NavSidebarItem>[
       (icon: PangolinIcons.power, label: t.tabConnect, view: NavView.connect),
       (icon: PangolinIcons.globe, label: t.tabServers, view: NavView.servers),
@@ -61,11 +62,19 @@ class TabletShell extends ConsumerWidget {
           return const SettingsPage();
         case NavView.contact:
           return const ContactPage();
+        case NavView.notifications:
+          return NotificationsScreen(t: t, embedded: true);
         default: // account / plans / redeem / devices → 账户（其余下钻在账户页内）
           return const AccountPage(isWide: true);
       }
     }
 
+    // 通知子页返回目标:回账户(镜像桌面 desktop_shell.dart::backTarget)。
+    VoidCallback? backTarget() {
+      if (view == NavView.notifications) return () => go(NavView.account);
+      return null;
+    }
+
     return ColoredBox(
       color: c.bg,
       // iPad 上内容会顶到状态栏(时间/电量/notch)。SafeArea 加顶部安全区,避开重叠;
@@ -76,7 +85,13 @@ class TabletShell extends ConsumerWidget {
           NavSidebar(items: items, width: 232, dense: false),
           Expanded(
             child: Column(children: [
-              ContentTopBar(title: titles[view] ?? t.tabMe, showThemeToggle: false, titleSize: 19),
+              ContentTopBar(
+                title: titles[view] ?? t.tabMe,
+                onBack: backTarget(),
+                onBell: () => go(NavView.notifications),
+                showThemeToggle: false,
+                titleSize: 19,
+              ),
               Expanded(child: content()),
             ]),
           ),

client/lib/widgets/account_screens.dart

@@ -20,39 +20,7 @@ import '../services/auth_api.dart';
 import '../state/account_providers.dart';
 import 'pangolin_button.dart';
 import 'pangolin_icons.dart';
-
-/// 通用:带返回箭头的子页骨架。embedded=true 时只返回内容（desktop 内容区下钻，
-/// 返回/标题由外层 shell 顶栏提供），否则整页 Scaffold（mobile/tablet 全屏 push）。
-class _SubScaffold extends StatelessWidget {
-  const _SubScaffold({required this.title, required this.child, this.onBack, this.embedded = false});
-  final String title;
-  final Widget child;
-  final VoidCallback? onBack;
-  final bool embedded;
-  @override
-  Widget build(BuildContext context) {
-    final c = context.pangolin;
-    if (embedded) return child;
-    return Scaffold(
-      backgroundColor: c.bg,
-      body: SafeArea(
-        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-          Padding(
-            padding: const EdgeInsets.fromLTRB(8, 6, 16, 10),
-            child: Row(children: [
-              IconButton(
-                onPressed: onBack ?? () => Navigator.of(context).maybePop(),
-                icon: Icon(PangolinIcons.arrowLeft, size: 22, color: c.fg1),
-              ),
-              Text(title, style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
-            ]),
-          ),
-          Expanded(child: child),
-        ]),
-      ),
-    );
-  }
-}
+import 'sub_scaffold.dart';
 
 /// ── 设置(移动端从「我的」下钻)── 复用桌面 SettingsPage 内容,套移动返回栏。
 class SettingsScreen extends StatelessWidget {
@@ -62,7 +30,7 @@ class SettingsScreen extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return _SubScaffold(title: t.settingsTitle, onBack: onBack, child: const SettingsPage());
+    return SubScaffold(title: t.settingsTitle, onBack: onBack, child: const SettingsPage());
   }
 }
 
@@ -113,7 +81,7 @@ class DevicesScreen extends ConsumerWidget {
           ]),
         );
 
-    return _SubScaffold(
+    return SubScaffold(
         title: t.myDevices, onBack: onBack, embedded: embedded, child: _DevicesAutoRefresh(child: content()));
   }
 
@@ -314,7 +282,7 @@ class _RedeemScreenState extends ConsumerState<RedeemScreen> {
   Widget build(BuildContext context) {
     final c = context.pangolin;
     final t = widget.t;
-    return _SubScaffold(
+    return SubScaffold(
       title: t.redeemTitle,
       onBack: widget.onBack,
       embedded: widget.embedded,
@@ -379,7 +347,7 @@ class ContactScreen extends StatelessWidget {
               accent: ch.accent,
             ))
         .toList();
-    return _SubScaffold(
+    return SubScaffold(
       title: t.contactTitle,
       onBack: onBack,
       child: ListView(padding: const EdgeInsets.fromLTRB(20, 4, 20, 24), children: [

client/lib/widgets/sub_scaffold.dart

@@ -0,0 +1,57 @@
+// sub_scaffold.dart — 通用「返回箭头 + 标题」子页脚手架(六处收敛,视觉零变化)。
+//
+// 收敛自 account_screens.dart/orders_page.dart 的私有 `_SubScaffold`,以及
+// purchase_page.dart/payment_page.dart/invite_page.dart/notifications_page.dart
+// 里结构相同的内联等价实现。逐像素沿用原实现(同 padding/字号/图标),纯收敛非重设计。
+//
+// embedded=true 时只返回内容(desktop 内容区下钻,返回/标题由外层 shell 顶栏提供);
+// 否则整页 Scaffold + SafeArea + 返回箭头行(mobile/tablet 全屏 push)。
+// wrapPageBody=true 时由本组件把 child 套进 PageBody(桌面内容页统一宽度容器);默认
+// false——调用方若已自行用 PageBody 包裹 child(如购买页需要 wide 变体),避免重复包裹。
+import 'package:flutter/material.dart';
+
+import '../pangolin_theme.dart';
+import 'page_body.dart';
+import 'pangolin_icons.dart';
+
+class SubScaffold extends StatelessWidget {
+  const SubScaffold({
+    super.key,
+    required this.title,
+    required this.child,
+    this.onBack,
+    this.embedded = false,
+    this.wrapPageBody = false,
+  });
+
+  final String title;
+  final Widget child;
+  final VoidCallback? onBack;
+  final bool embedded;
+  final bool wrapPageBody;
+
+  @override
+  Widget build(BuildContext context) {
+    final c = context.pangolin;
+    final body = wrapPageBody ? PageBody(child: child) : child;
+    if (embedded) return body;
+    return Scaffold(
+      backgroundColor: c.bg,
+      body: SafeArea(
+        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
+          Padding(
+            padding: const EdgeInsets.fromLTRB(8, 6, 16, 10),
+            child: Row(children: [
+              IconButton(
+                onPressed: onBack ?? () => Navigator.of(context).maybePop(),
+                icon: Icon(PangolinIcons.arrowLeft, size: 22, color: c.fg1),
+              ),
+              Text(title, style: PangolinText.h3.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
+            ]),
+          ),
+          Expanded(child: body),
+        ]),
+      ),
+    );
+  }
+}