fix(c2c): 我的订单显示用户角色视角，修复详情页缓存

1. "我的"列表根据用户是maker/taker判断实际角色，
   接买单(taker)时显示"卖出"而非"买入"
2. 订单详情 provider 改为 autoDispose，每次进入详情页
   都从API获取最新数据，避免显示旧的数量和状态

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/mining-app/lib/presentation/pages/c2c/c2c_market_page.dart

@@ -100,7 +100,7 @@ class _C2cMarketPageState extends ConsumerState<C2cMarketPage>
               children: [
                 _buildOrderList(context, 'SELL'), // 购买页面显示卖单
                 _buildOrderList(context, 'BUY'),  // 出售页面显示买单
-                _buildMyOrderList(context),
+                _buildMyOrderList(context, accountSequence),
               ],
             ),
           ),
@@ -233,7 +233,7 @@ class _C2cMarketPageState extends ConsumerState<C2cMarketPage>
     );
   }
 
-  Widget _buildMyOrderList(BuildContext context) {
+  Widget _buildMyOrderList(BuildContext context, String accountSequence) {
     final ordersAsync = ref.watch(myC2cOrdersProvider);
 
     return ordersAsync.when(
@@ -277,7 +277,7 @@ class _C2cMarketPageState extends ConsumerState<C2cMarketPage>
             itemCount: orders.length,
             itemBuilder: (context, index) {
               final order = orders[index];
-              return _buildMyOrderCard(context, order);
+              return _buildMyOrderCard(context, order, accountSequence);
             },
           ),
         );
@@ -439,8 +439,14 @@ class _C2cMarketPageState extends ConsumerState<C2cMarketPage>
     );
   }
 
-  Widget _buildMyOrderCard(BuildContext context, C2cOrderModel order) {
+  Widget _buildMyOrderCard(BuildContext context, C2cOrderModel order, String accountSequence) {
     final isDark = AppColors.isDark(context);
+    // 判断当前用户在这笔订单中的角色（买方/卖方）
+    // maker 创建订单: BUY→maker是买方, SELL→maker是卖方
+    // taker 接单:     BUY→taker是卖方, SELL→taker是买方
+    final isMaker = order.makerAccountSequence == accountSequence;
+    final isUserBuying = (isMaker && order.isBuy) || (!isMaker && order.isSell);
+
     return GestureDetector(
       onTap: () => context.push(Routes.c2cOrderDetail, extra: order.orderNo),
       child: Container(
@@ -462,15 +468,15 @@ class _C2cMarketPageState extends ConsumerState<C2cMarketPage>
                     Container(
                       padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                       decoration: BoxDecoration(
-                        color: (order.isBuy ? _green : _red).withOpacity(isDark ? 0.2 : 0.1),
+                        color: (isUserBuying ? _green : _red).withOpacity(isDark ? 0.2 : 0.1),
                         borderRadius: BorderRadius.circular(4),
                       ),
                       child: Text(
-                        order.typeText,
+                        isUserBuying ? '买入' : '卖出',
                         style: TextStyle(
                           fontSize: 12,
                           fontWeight: FontWeight.bold,
-                          color: order.isBuy ? _green : _red,
+                          color: isUserBuying ? _green : _red,
                         ),
                       ),
                     ),

frontend/mining-app/lib/presentation/providers/c2c_providers.dart

@@ -36,8 +36,8 @@ final myC2cOrdersProvider = FutureProvider<C2cOrdersPageModel>(
   },
 );
 
-/// C2C订单详情 Provider
-final c2cOrderDetailProvider = FutureProvider.family<C2cOrderModel, String>(
+/// C2C订单详情 Provider（autoDispose: 每次进入详情页都获取最新数据）
+final c2cOrderDetailProvider = FutureProvider.autoDispose.family<C2cOrderModel, String>(
   (ref, orderNo) async {
     final dataSource = getIt<TradingRemoteDataSource>();
     return dataSource.getC2cOrderDetail(orderNo);