feat: 添加订单大厅看板 API（四列数据 + 统计 + 重连补偿 + 操作端点）

- 新增 OrderBoardCardDto、OrderBoardResultDto、OrderBoardStatsDto
- 新增看板查询 Query + Handler（board/stats/pending-since）
- IOrderRepository 扩展 GetActiveOrdersAsync、GetOrdersChangedSinceAsync
- EfOrderRepository 实现看板查询方法
- 新增 OrderBoardController（GET board/stats/pending-since + POST accept/reject/complete/confirm）
- 新增 RejectOrderRequest 契约

src/Infrastructure/TakeoutSaaS.Infrastructure/App/Repositories/EfOrderRepository.cs

@@ -313,6 +313,35 @@ public sealed class EfOrderRepository(TakeoutAppDbContext context) : IOrderRepos
         context.Orders.Remove(existing);
     }
 
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<Order>> GetActiveOrdersAsync(long tenantId, long storeId, CancellationToken cancellationToken = default)
+    {
+        // 查询待接单、制作中、待取餐的活跃订单
+        var activeStatuses = new[]
+        {
+            OrderStatus.AwaitingPreparation,
+            OrderStatus.InProgress,
+            OrderStatus.Ready
+        };
+
+        return await context.Orders
+            .AsNoTracking()
+            .Where(x => x.TenantId == tenantId && x.StoreId == storeId && activeStatuses.Contains(x.Status))
+            .OrderBy(x => x.CreatedAt)
+            .ToListAsync(cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<Order>> GetOrdersChangedSinceAsync(long tenantId, long storeId, DateTime since, CancellationToken cancellationToken = default)
+    {
+        // 查询指定时间后创建或更新的订单
+        return await context.Orders
+            .AsNoTracking()
+            .Where(x => x.TenantId == tenantId && x.StoreId == storeId && x.UpdatedAt >= since)
+            .OrderByDescending(x => x.UpdatedAt)
+            .ToListAsync(cancellationToken);
+    }
+
     private IQueryable<Order> BuildSearchAllOrdersQuery(
         long tenantId,
         long? storeId,