fix(traffic): re-enable clients and serialize the write in Reset All Client Traffic

ClientService.ResetAllTraffics zeroed up/down but, unlike every sibling reset
path, never restored enable=true, so clients that had been auto-disabled for
exceeding their quota stayed cut with zero usage after a reset. It also wrote
client_traffics directly on the shared DB handle instead of through the serial
traffic writer, reintroducing the cross-transaction lock-order deadlock the
writer exists to prevent. Restore enable and run the reset inside
submitTrafficWrite within one transaction.

internal/web/service/client_traffic.go

@@ -200,15 +200,21 @@ func (s *ClientService) resetAllClientTrafficsLocked(id int) error {
 }
 
 func (s *ClientService) ResetAllTraffics() (bool, error) {
-	db := database.GetDB()
-	res := db.Model(&xray.ClientTraffic{}).
-		Where("1 = 1").
-		Updates(map[string]any{"up": 0, "down": 0})
-	if res.Error != nil {
-		return false, res.Error
-	}
-	if err := db.Where("1 = 1").Delete(&model.ClientGlobalTraffic{}).Error; err != nil {
+	var affected int64
+	err := submitTrafficWrite(func() error {
+		return database.GetDB().Transaction(func(tx *gorm.DB) error {
+			res := tx.Model(&xray.ClientTraffic{}).
+				Where("1 = 1").
+				Updates(map[string]any{"enable": true, "up": 0, "down": 0})
+			if res.Error != nil {
+				return res.Error
+			}
+			affected = res.RowsAffected
+			return tx.Where("1 = 1").Delete(&model.ClientGlobalTraffic{}).Error
+		})
+	})
+	if err != nil {
 		return false, err
 	}
-	return res.RowsAffected > 0, nil
+	return affected > 0, nil
 }