fix(mining-app): 统一贡献值页与兑换页的剩余积分股计算方式

贡献值页原先使用 sharePoolBalance API (Pool A + Pool B 余额) 显示剩余积分股,
兑换页使用公式 totalShares - totalMined - blackHoleAmount 计算。
两者显示结果不一致 (差异约 228,343 积分股)。

根本原因调查:
- mining-wallet-service 的 Kafka 消费者在服务重启期间丢失了部分事件
- Pool B 仅处理了 15.7% 的挖矿分配事件 (28,261/180,497)
- Pool A 遗漏了 66,591 笔销毁扣减事件
- 池账户余额是通过 Kafka 事件维护的记账台账，存在消费遗漏
- totalShares - totalMined - blackHoleAmount 公式基于实际挖矿和销毁数据计算，是数学上的 ground truth
- 实际用户分配和销毁均 100% 准确，仅池账户记账有偏差

修复方案:
- 贡献值页改用 marketOverviewProvider (同兑换页)
- 使用公式 totalShares - totalMined - blackHoleAmount 计算剩余积分股
- 两个页面现在显示完全一致的数据

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/mining-app/lib/presentation/pages/contribution/contribution_page.dart

@@ -1,3 +1,4 @@
+import 'package:decimal/decimal.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
@@ -5,10 +6,12 @@ import '../../../core/constants/app_colors.dart';
 import '../../../core/router/routes.dart';
 import '../../../core/utils/format_utils.dart';
 import '../../../domain/entities/contribution.dart';
+import '../../../domain/entities/market_overview.dart';
 import '../../../domain/entities/share_account.dart';
 import '../../providers/user_providers.dart';
 import '../../providers/contribution_providers.dart';
 import '../../providers/mining_providers.dart';
+import '../../providers/trading_providers.dart';
 import '../../widgets/shimmer_loading.dart';
 
 class ContributionPage extends ConsumerWidget {
@@ -25,8 +28,8 @@ class ContributionPage extends ConsumerWidget {
     final contributionAsync = ref.watch(contributionProvider(accountSequence));
     // 获取预估收益（基于用户每秒收益计算）
     final estimatedEarnings = ref.watch(estimatedEarningsProvider(accountSequence));
-    // 获取积分股池余量
-    final sharePoolAsync = ref.watch(sharePoolBalanceProvider);
+    // 获取市场概览（用于计算剩余积分股 = totalShares - totalMined - blackHoleAmount）
+    final marketAsync = ref.watch(marketOverviewProvider);
     // 获取挖矿账户信息（含首次挖矿时间，用于730天倒计时）
     final shareAccountAsync = ref.watch(shareAccountProvider(accountSequence));
 
@@ -35,8 +38,8 @@ class ContributionPage extends ConsumerWidget {
     final contribution = contributionAsync.valueOrNull;
     final hasError = contributionAsync.hasError;
     final error = contributionAsync.error;
-    final isSharePoolLoading = sharePoolAsync.isLoading;
-    final sharePoolBalance = sharePoolAsync.valueOrNull;
+    final isMarketLoading = marketAsync.isLoading;
+    final market = marketAsync.valueOrNull;
 
     return Scaffold(
       backgroundColor: AppColors.backgroundOf(context),
@@ -45,7 +48,7 @@ class ContributionPage extends ConsumerWidget {
         child: RefreshIndicator(
           onRefresh: () async {
             ref.invalidate(contributionProvider(accountSequence));
-            ref.invalidate(sharePoolBalanceProvider);
+            ref.invalidate(marketOverviewProvider);
             ref.invalidate(shareAccountProvider(accountSequence));
           },
           child: hasError && contribution == null
@@ -74,7 +77,7 @@ class ContributionPage extends ConsumerWidget {
                       sliver: SliverList(
                         delegate: SliverChildListDelegate([
                           // 总贡献值卡片
-                          _buildTotalContributionCard(context, ref, contribution, isLoading, sharePoolBalance, isSharePoolLoading),
+                          _buildTotalContributionCard(context, ref, contribution, isLoading, market, isMarketLoading),
                           const SizedBox(height: 16),
                           // 三栏统计
                           _buildThreeColumnStats(context, ref, contribution, isLoading),
@@ -165,8 +168,8 @@ class ContributionPage extends ConsumerWidget {
     WidgetRef ref,
     Contribution? contribution,
     bool isLoading,
-    SharePoolBalance? sharePoolBalance,
-    bool isSharePoolLoading,
+    MarketOverview? market,
+    bool isMarketLoading,
   ) {
     final isDark = AppColors.isDark(context);
     final total = contribution?.totalContribution ?? '0';
@@ -219,13 +222,21 @@ class ContributionPage extends ConsumerWidget {
                 '100亿销毁剩余量: ',
                 style: TextStyle(fontSize: 12, color: AppColors.textSecondaryOf(context)),
               ),
-              isSharePoolLoading
+              isMarketLoading
                   ? const ShimmerText(
                       placeholder: '----',
                       style: TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: _orange),
                     )
                   : Text(
-                      hideAmounts ? '******' : formatAmount(sharePoolBalance?.total ?? '0'),
+                      hideAmounts
+                          ? '******'
+                          : market != null
+                              ? formatAmount(
+                                  (Decimal.parse(market.totalShares) -
+                                          Decimal.parse(market.totalMined) -
+                                          Decimal.parse(market.blackHoleAmount))
+                                      .toString())
+                              : '0',
                       style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: _orange),
                     ),
             ],