feat(client): P3 账号/套餐视角/配额接真(#6 6C)

- account_providers:新增 meProvider(GET /v1/me,登录态变化自动重取)、
  plansProvider、usageProvider(family by days)。
- isFreePlanProvider 改为派生自 meProvider.plan(去掉可写演示开关)。
- quotaProvider:总额取 plans free.daily_minutes,今日剩余取 me.quota_today_min
  (后端已算好);adUnlocked 保留本地态(ad SDK 未接)。
- account_page:邮箱/套餐/到期接 me;删「演示:免费版视角」开关 + kDemoEmail;
  协议标签 WireGuard→REALITY/Hysteria2。
- 重写 quota_controller_test 为 provider 驱动;account/quota golden 重生成。

flutter analyze 0 error;113 tests passed。统计页(weekly/月流量/延迟)随 P4
一并接(其均延迟依赖 P4 实测探针)。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/lib/models/me.dart

@@ -28,7 +28,8 @@ class Me {
   final int devicesUsed;
   final int devicesMax;
 
-  /// 今日额度上限(分钟);null = 不限(pro/team)。
+  /// 今日**剩余**额度(分钟);null = 不限(pro/team)。
+  /// 后端已算好 = 套餐每日上限 − 今日已用。
   final int? quotaTodayMin;
 
   /// 今日已用流量(GB)。

client/lib/screens/account_page.dart

@@ -5,13 +5,19 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import '../core/responsive/form_factor.dart';
 import '../l10n/app_text.dart';
 import '../pangolin_theme.dart';
+import '../state/account_providers.dart';
 import '../state/app_providers.dart';
 import '../state/navigation_provider.dart';
 import '../widgets/account_screens.dart';
 import '../widgets/app_top_bar.dart';
 import '../widgets/pangolin_icons.dart';
 
-const String kDemoEmail = 'me@pangolin.vpn';
+/// 格式化到期日为 YYYY-MM-DD(本地时区)。
+String _fmtDate(DateTime d) {
+  final l = d.toLocal();
+  String two(int v) => v.toString().padLeft(2, '0');
+  return '${l.year}-${two(l.month)}-${two(l.day)}';
+}
 
 class AccountPage extends ConsumerWidget {
   const AccountPage({super.key, required this.isWide});
@@ -22,6 +28,9 @@ class AccountPage extends ConsumerWidget {
     final c = context.pangolin;
     final t = ref.watch(appTextProvider);
     final isFree = ref.watch(isFreePlanProvider);
+    final me = ref.watch(meProvider).valueOrNull;
+    final email = (me?.email.isNotEmpty ?? false) ? me!.email : '—';
+    final expiresLabel = me?.expiresAt != null ? _fmtDate(me!.expiresAt!) : '';
     final lang = ref.watch(localeProvider);
     final isDark = Theme.of(context).brightness == Brightness.dark;
     final pad = isWide ? 28.0 : 20.0;
@@ -39,12 +48,12 @@ class AccountPage extends ConsumerWidget {
     final body = ListView(
       padding: EdgeInsets.fromLTRB(pad, isWide ? 6 : 0, pad, 24),
       children: [
-        _PlanBanner(t: t, isFree: isFree, onUpgrade: () => open(NavView.plans, PlansScreen(t: t))),
+        _PlanBanner(t: t, isFree: isFree, email: email, expiresLabel: expiresLabel, onUpgrade: () => open(NavView.plans, PlansScreen(t: t))),
         const SizedBox(height: 18),
         // 账户信息
         _SectionLabel(text: t.accInfoTitle),
         _Card(children: [
-          _InfoRow(icon: PangolinIcons.mail, title: t.accEmail, value: kDemoEmail, trailing: _changeHint(c, t)),
+          _InfoRow(icon: PangolinIcons.mail, title: t.accEmail, value: email, trailing: _changeHint(c, t)),
           Divider(height: 1, color: c.border),
           _InfoRow(icon: PangolinIcons.lock, title: t.accPassword, value: '••••••••••', trailing: _changeHint(c, t)),
         ]),
@@ -79,20 +88,7 @@ class AccountPage extends ConsumerWidget {
           _CustomRow(
             icon: PangolinIcons.shield,
             title: t.protocol,
-            trailing: Text('WireGuard', style: PangolinText.mono.copyWith(color: c.fg3, fontSize: 13)),
-          ),
-        ]),
-        const SizedBox(height: 16),
-        // 演示:免费版视角开关
-        _Card(children: [
-          _CustomRow(
-            icon: PangolinIcons.clock,
-            title: lang == AppLang.zh ? '演示:免费版视角' : 'Demo: free-tier view',
-            subtitle: lang == AppLang.zh ? '切换额度卡与套餐横幅' : 'Toggles quota UI & plan banner',
-            trailing: _PangolinSwitch(
-              value: isFree,
-              onChanged: (v) => ref.read(isFreePlanProvider.notifier).state = v,
-            ),
+            trailing: Text('REALITY / Hysteria2', style: PangolinText.mono.copyWith(color: c.fg3, fontSize: 13)),
           ),
         ]),
         const SizedBox(height: 16),
@@ -115,9 +111,17 @@ class AccountPage extends ConsumerWidget {
 }
 
 class _PlanBanner extends StatelessWidget {
-  const _PlanBanner({required this.t, required this.isFree, required this.onUpgrade});
+  const _PlanBanner({
+    required this.t,
+    required this.isFree,
+    required this.email,
+    required this.expiresLabel,
+    required this.onUpgrade,
+  });
   final AppText t;
   final bool isFree;
+  final String email;
+  final String expiresLabel;
   final VoidCallback onUpgrade;
 
   @override
@@ -141,7 +145,7 @@ class _PlanBanner extends StatelessWidget {
             ),
             const SizedBox(width: 12),
             Expanded(child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-              Text(kDemoEmail, style: PangolinText.body.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
+              Text(email, style: PangolinText.body.copyWith(color: c.fg1, fontWeight: FontWeight.w700)),
               const SizedBox(height: 4),
               Container(
                 padding: const EdgeInsets.symmetric(horizontal: 9, vertical: 2),
@@ -173,9 +177,9 @@ class _PlanBanner extends StatelessWidget {
         ),
         const SizedBox(width: 12),
         Expanded(child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-          Text(kDemoEmail, style: const TextStyle(color: PangolinColors.white, fontWeight: FontWeight.w700, fontSize: 16)),
+          Text(email, style: const TextStyle(color: PangolinColors.white, fontWeight: FontWeight.w700, fontSize: 16)),
           const SizedBox(height: 4),
-          Text('${t.proMember} · 2026-12-31',
+          Text(expiresLabel.isEmpty ? t.proMember : '${t.proMember} · $expiresLabel',
               style: TextStyle(color: PangolinColors.white.withOpacity(0.85), fontSize: 12)),
         ])),
         FilledButton(

client/lib/state/account_providers.dart

@@ -5,6 +5,9 @@
 // 在后续阶段加入本文件。
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import '../models/me.dart';
+import '../models/plan.dart';
+import '../models/usage_point.dart';
 import '../services/account_api.dart';
 import '../services/api_client.dart';
 import '../services/api_config.dart';
@@ -23,3 +26,35 @@ final apiClientProvider = Provider<ApiClient>((ref) {
 final accountApiProvider = Provider<AccountApi>(
   (ref) => AccountApi(ref.watch(apiClientProvider)),
 );
+
+// ── 数据 provider ───────────────────────────────────────────────────────────
+
+/// 当前账户聚合视图(GET /v1/me)。登录态变化自动重取;未登录返回默认免费档。
+class MeNotifier extends AsyncNotifier<Me> {
+  @override
+  Future<Me> build() async {
+    final auth = ref.watch(authProvider);
+    if (!auth.isLoggedIn) return const Me(email: '', plan: 'free');
+    return ref.read(accountApiProvider).me();
+  }
+
+  /// 手动刷新(如连接/兑换后)。
+  Future<void> refresh() async {
+    state = const AsyncLoading();
+    state = await AsyncValue.guard(() => ref.read(accountApiProvider).me());
+  }
+}
+
+final meProvider = AsyncNotifierProvider<MeNotifier, Me>(MeNotifier.new);
+
+/// 套餐定义(GET /v1/plans)。未登录返回空。
+final plansProvider = FutureProvider<List<Plan>>((ref) async {
+  if (!ref.watch(authProvider).isLoggedIn) return const [];
+  return ref.read(accountApiProvider).plans();
+});
+
+/// 最近 N 天用量(GET /v1/usage?days=N)。未登录返回空。
+final usageProvider = FutureProvider.family<List<UsagePoint>, int>((ref, days) async {
+  if (!ref.watch(authProvider).isLoggedIn) return const [];
+  return ref.read(accountApiProvider).usage(days: days);
+});

client/lib/state/app_providers.dart

@@ -5,6 +5,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import '../l10n/app_text.dart';
 import '../l10n/strings_en.dart';
 import '../l10n/strings_zh.dart';
+import 'account_providers.dart';
 
 /// 当前语言(单显)。设置/账户页段控切换。
 final localeProvider = StateProvider<AppLang>((ref) => AppLang.zh);
@@ -18,5 +19,9 @@ final appTextProvider = Provider<AppText>((ref) {
 /// 主题模式。默认跟随系统;设置页可显式切深色。
 final themeModeProvider = StateProvider<ThemeMode>((ref) => ThemeMode.system);
 
-/// 演示:是否「免费版视角」。免费版才显示额度卡与免费横幅。
-final isFreePlanProvider = StateProvider<bool>((ref) => true);
+/// 是否免费档——派生自真实账户(meProvider.plan == 'free')。
+/// 免费版才显示额度卡与免费横幅;加载中默认按免费处理。
+final isFreePlanProvider = Provider<bool>((ref) {
+  final me = ref.watch(meProvider).valueOrNull;
+  return me?.isFree ?? true;
+});

client/lib/state/quota_provider.dart

@@ -1,15 +1,18 @@
-// quota_provider.dart — 免费版每日额度状态机(Riverpod,mock 数据)
+// quota_provider.dart — 免费版每日额度状态(Riverpod)
 //
-// 设计约定(design/CLAUDE.md §7 / §2):免费额度权威在服务端,本地仅展示。
-// 这里以 mock 实现 UI 与数据层解耦的接口形态:剩余分钟 + 是否已看广告解锁。
-// 接 API 时只替换本通知器内部,UI 不动。
+// 设计约定(design/CLAUDE.md §7 / §2):免费额度权威在服务端。
+// 总额度取自 plans 的 free.daily_minutes,今日剩余取自 me.quota_today_min
+// (后端已算好 = 上限 − 今日已用)。adUnlocked 为本地会话态(看广告需 ad SDK,
+// 尚未接入,保留本地乐观置位)。
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
+import 'account_providers.dart';
+
 /// 免费额度快照。
 class FreeQuotaState {
   const FreeQuotaState({
     this.totalMinutes = 10,
-    this.remainingMinutes = 6,
+    this.remainingMinutes = 10,
     this.adUnlocked = false,
   });
 
@@ -38,16 +41,32 @@ class FreeQuotaState {
 }
 
 class QuotaController extends StateNotifier<FreeQuotaState> {
-  QuotaController([FreeQuotaState? initial])
-      : super(initial ?? const FreeQuotaState());
+  QuotaController(this._ref) : super(const FreeQuotaState()) {
+    _sync();
+    // me / plans 任一就绪或变化都重算。
+    _ref.listen(meProvider, (_, __) => _sync());
+    _ref.listen(plansProvider, (_, __) => _sync());
+  }
 
-  /// 观看激励视频后解锁今日使用。
+  final Ref _ref;
+
+  void _sync() {
+    final me = _ref.read(meProvider).valueOrNull;
+    final plans = _ref.read(plansProvider).valueOrNull;
+    var total = 10; // §7 默认免费 10 分钟,plans 就绪后以其为准
+    if (plans != null) {
+      for (final p in plans) {
+        if (p.code == 'free' && p.dailyMinutes != null) total = p.dailyMinutes!;
+      }
+    }
+    final remaining = (me?.quotaTodayMin ?? total).clamp(0, total);
+    state = state.copyWith(totalMinutes: total, remainingMinutes: remaining);
+  }
+
+  /// 观看激励视频后解锁今日使用(本地乐观;真实 ad 校验待 ad SDK 接入)。
   void watchAd() => state = state.copyWith(adUnlocked: true);
-
-  /// 演示重置(回到未解锁)。
-  void reset() => state = const FreeQuotaState();
 }
 
 final quotaProvider = StateNotifierProvider<QuotaController, FreeQuotaState>(
-  (ref) => QuotaController(),
+  (ref) => QuotaController(ref),
 );

client/test/unit/quota_controller_test.dart

@@ -1,36 +1,60 @@
-// quota_controller_test.dart — 免费额度状态机
+// quota_controller_test.dart — 免费额度状态(派生自 me/plans)
+import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:pangolin_vpn/services/token_store.dart';
+import 'package:pangolin_vpn/state/auth_provider.dart';
 import 'package:pangolin_vpn/state/quota_provider.dart';
 
+// 避免触碰真实 FlutterSecureStorage 插件(单测无平台)。
+class _NullTokenStore implements TokenStore {
+  const _NullTokenStore();
+  @override
+  Future<void> saveTokens({required String access, required String refresh}) async {}
+  @override
+  Future<String?> loadAccessToken() async => null;
+  @override
+  Future<String?> loadRefreshToken() async => null;
+  @override
+  Future<void> clear() async {}
+  @override
+  Future<void> markOnboarded() async {}
+  @override
+  Future<bool> isOnboarded() async => true;
+}
+
+ProviderContainer _container() => ProviderContainer(
+      overrides: [tokenStoreProvider.overrideWithValue(const _NullTokenStore())],
+    );
+
 void main() {
-  test('默认值:10 分钟总额 / 6 分钟剩余 / 未解锁', () {
-    final ctl = QuotaController();
-    expect(ctl.state.totalMinutes, 10);
-    expect(ctl.state.remainingMinutes, 6);
-    expect(ctl.state.adUnlocked, false);
+  // 纯状态逻辑(与数据源无关)。
+  group('FreeQuotaState', () {
+    test('progress = 剩余/总额', () {
+      expect(const FreeQuotaState(totalMinutes: 10, remainingMinutes: 5).progress,
+          closeTo(0.5, 1e-9));
+    });
+    test('isLow:剩余 ≤3 分钟为真', () {
+      expect(const FreeQuotaState(remainingMinutes: 3).isLow, true);
+      expect(const FreeQuotaState(remainingMinutes: 4).isLow, false);
+    });
   });
 
-  test('progress = 剩余/总额', () {
-    final ctl = QuotaController(const FreeQuotaState(totalMinutes: 10, remainingMinutes: 5));
-    expect(ctl.state.progress, closeTo(0.5, 1e-9));
-  });
+  // 未登录默认态:总额 10 / 剩余 10 / 未解锁;watchAd 本地置位。
+  group('quotaProvider', () {
+    test('默认 10/10 未解锁', () {
+      final c = _container();
+      addTearDown(c.dispose);
+      final q = c.read(quotaProvider);
+      expect(q.totalMinutes, 10);
+      expect(q.remainingMinutes, 10);
+      expect(q.adUnlocked, false);
+    });
 
-  test('isLow:剩余 ≤3 分钟为真', () {
-    expect(const FreeQuotaState(remainingMinutes: 3).isLow, true);
-    expect(const FreeQuotaState(remainingMinutes: 4).isLow, false);
-  });
-
-  test('watchAd 解锁今日使用', () {
-    final ctl = QuotaController();
-    expect(ctl.state.adUnlocked, false);
-    ctl.watchAd();
-    expect(ctl.state.adUnlocked, true);
-  });
-
-  test('reset 回到未解锁初始态', () {
-    final ctl = QuotaController()..watchAd();
-    ctl.reset();
-    expect(ctl.state.adUnlocked, false);
-    expect(ctl.state.remainingMinutes, 6);
+    test('watchAd 解锁今日使用', () {
+      final c = _container();
+      addTearDown(c.dispose);
+      c.read(quotaProvider.notifier).watchAd();
+      expect(c.read(quotaProvider).adUnlocked, true);
+    });
   });
 }