fix(channel): 统一渠道分析时间筛选范围

让渠道分析弹窗的概览卡片和趋势图共用同一时间筛选范围，
并将默认行为调整为历史全量展示。前端改为在未选择日期时
不再回退最近 12 天，后端新增统一时间窗口解析逻辑，使
overview 与 daily 在全量、指定区间和 days 模式下保持一致。

internal/service/channel/channel.go

@@ -396,6 +396,46 @@ func (s *service) List(ctx context.Context, in ListInput) (items []*ChannelWithS
 	return
 }
 
+func (s *service) resolveStatsRange(ctx context.Context, channelID int64, days int, startDateStr, endDateStr string, now time.Time) (*time.Time, *time.Time, error) {
+	if startDateStr != "" && endDateStr != "" {
+		startDate, err := time.ParseInLocation("2006-01-02", startDateStr, time.Local)
+		if err != nil {
+			return nil, nil, err
+		}
+		endDate, err := time.ParseInLocation("2006-01-02", endDateStr, time.Local)
+		if err != nil {
+			return nil, nil, err
+		}
+		endDate = endDate.Add(24*time.Hour - time.Second)
+		return &startDate, &endDate, nil
+	}
+
+	if days > 0 {
+		startDate := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location()).AddDate(0, 0, -days+1)
+		endDate := now
+		return &startDate, &endDate, nil
+	}
+
+	type minTimeRow struct {
+		MinCreatedAt *time.Time `gorm:"column:min_created_at"`
+	}
+	var row minTimeRow
+	err := s.readDB.Orders.WithContext(ctx).UnderlyingDB().Table("orders").
+		Joins("JOIN users ON users.id = orders.user_id").
+		Select("MIN(orders.created_at) as min_created_at").
+		Where("users.channel_id = ? AND users.deleted_at IS NULL AND orders.status = 2 AND orders.total_amount > 0 AND orders.actual_amount > 0 AND orders.source_type IN (2,3,4) AND (orders.ext_order_id = '' OR orders.ext_order_id IS NULL)", channelID).
+		Scan(&row).Error
+	if err != nil {
+		return nil, nil, err
+	}
+	if row.MinCreatedAt == nil {
+		return nil, nil, nil
+	}
+	startDate := time.Date(row.MinCreatedAt.Year(), row.MinCreatedAt.Month(), row.MinCreatedAt.Day(), 0, 0, 0, 0, now.Location())
+	endDate := now
+	return &startDate, &endDate, nil
+}
+
 func (s *service) GetStats(ctx context.Context, channelID int64, days int, startDateStr, endDateStr string) (*StatsOutput, error) {
 	now := time.Now()
 
@@ -411,49 +451,53 @@ func (s *service) GetStats(ctx context.Context, channelID int64, days int, start
 	// source_type: 2=小程序抽奖 3=对对碰 4=一番赏/次卡 5=直播间抽奖抖店(不计入)；排除商城直购(1)
 	// actual_amount>0 排除次卡免费使用的订单（避免与购买次卡的订单重复计入GMV）
 	orderFilter := "users.channel_id = ? AND users.deleted_at IS NULL AND orders.status = 2 AND orders.total_amount > 0 AND orders.actual_amount > 0 AND orders.source_type IN (2,3,4) AND (orders.ext_order_id = '' OR orders.ext_order_id IS NULL)"
+	statsStart, statsEnd, err := s.resolveStatsRange(ctx, channelID, days, startDateStr, endDateStr, now)
+	if err != nil {
+		return nil, err
+	}
 
-	// ========== 1. Overview（全量，不限时间）==========
+	// ========== 1. Overview（与当前筛选窗口保持一致）==========
 
-	userCount, _ := s.readDB.Users.WithContext(ctx).Where(s.readDB.Users.ChannelID.Eq(channelID)).Count()
+	userCountQuery := s.readDB.Users.WithContext(ctx)
+	if statsStart != nil && statsEnd != nil {
+		userCountQuery = userCountQuery.Where(s.readDB.Users.CreatedAt.Gte(*statsStart)).Where(s.readDB.Users.CreatedAt.Lte(*statsEnd))
+	}
+	userCount, _ := userCountQuery.Where(s.readDB.Users.ChannelID.Eq(channelID)).Count()
 	out.Overview.TotalUsers = userCount
 
 	type countResult struct{ Count int64 }
 	var cr countResult
-	s.readDB.Orders.WithContext(ctx).UnderlyingDB().Table("orders").
+	overviewOrders := s.readDB.Orders.WithContext(ctx).UnderlyingDB().Table("orders").
 		Joins("JOIN users ON users.id = orders.user_id").
 		Select("count(*) as count").
-		Where(orderFilter, channelID).
-		Scan(&cr)
+		Where(orderFilter, channelID)
+	if statsStart != nil && statsEnd != nil {
+		overviewOrders = overviewOrders.Where("orders.created_at >= ? AND orders.created_at <= ?", *statsStart, *statsEnd)
+	}
+	overviewOrders.Scan(&cr)
 	out.Overview.TotalOrders = cr.Count
 
-	totalGMV, _ := s.calcGMVByTotalAmount(ctx, channelID, "2006-01-02", orderFilter, nil, nil)
+	totalGMV, _ := s.calcGMVByTotalAmount(ctx, channelID, "2006-01-02", orderFilter, statsStart, statsEnd)
 	out.Overview.TotalPaidCents = totalGMV.Total
 	out.Overview.TotalGMV = totalGMV.Total / 100
 	out.Overview.CashCents = totalGMV.Cash
 	out.Overview.CouponCents = totalGMV.Coupon
 	out.Overview.PointsCents = totalGMV.Points
 
-		// 1d. 累计成本（全量，按原始订单/抽奖来源归因）
-	totalCost, _ := s.calcCostByDrawSource(ctx, channelID, "2006-01-02", nil, nil)
+	// 1d. 累计成本（当前筛选窗口，按原始订单/抽奖来源归因）
+	totalCost, _ := s.calcCostByDrawSource(ctx, channelID, "2006-01-02", statsStart, statsEnd)
 	out.Overview.TotalCostCents = totalCost
 	out.Overview.TotalCost = totalCost / 100
 	out.Overview.TotalProfitCents = totalGMV.Total - totalCost
 	out.Overview.TotalProfit = out.Overview.TotalProfitCents / 100
 
-	// ========== 2. 趋势图（按天分组，受 days 限制）==========
+	// ========== 2. 趋势图（按天分组，与 overview 保持相同时间窗口）==========
 
-	var startDate, endDate time.Time
-	if startDateStr != "" && endDateStr != "" {
-		startDate, _ = time.Parse("2006-01-02", startDateStr)
-		endDate, _ = time.Parse("2006-01-02", endDateStr)
-		endDate = endDate.Add(24*time.Hour - time.Second)
-	} else {
-		if days <= 0 {
-			days = 12
-		}
-		startDate = time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location()).AddDate(0, 0, -days+1)
-		endDate = now
+	if statsStart == nil || statsEnd == nil {
+		return out, nil
 	}
+	startDate := *statsStart
+	endDate := *statsEnd
 
 	dateMap := make(map[string]*StatsDailyItem)
 	var dateList []string