fix(sub): close a deleted host binding only on the inbound it served

Deleting the only host a client was bound to blanked that client on every
inbound. Once the host row was gone, the binding could no longer say which
inbound it guarded, so it failed closed everywhere: a client on inbounds A
and B, bound to one host on A, lost B's link the moment that host was
deleted, and nothing in the panel hinted at it.

Every host delete (host groups, the externalProxy sync, inbound deletion,
the depleted-inbound sweep and the orphan prune) now goes through
database.DeleteHosts, which keeps each deleted host's inbound in
host_tombstones in the same transaction. A binding to a deleted host closes
only that inbound; ids that resolve to no host at all still fail closed
everywhere. The Postgres Host step now runs the deletion cases as well.

internal/web/service/host.go

@@ -337,7 +337,7 @@ func (s *HostService) UpdateHostGroup(groupId string, req *entity.HostGroup) ([]
 			}
 		}
 		if len(toDelete) > 0 {
-			if err := tx.Where("id IN ?", toDelete).Delete(&model.Host{}).Error; err != nil {
+			if _, err := database.DeleteHosts(tx, "id IN ?", toDelete); err != nil {
 				return err
 			}
 		}
@@ -360,7 +360,10 @@ func (s *HostService) UpdateHostGroup(groupId string, req *entity.HostGroup) ([]
 }
 
 func (s *HostService) DeleteHostGroup(groupId string) error {
-	return database.GetDB().Where("group_id = ?", groupId).Delete(&model.Host{}).Error
+	return database.GetDB().Transaction(func(tx *gorm.DB) error {
+		_, err := database.DeleteHosts(tx, "group_id = ?", groupId)
+		return err
+	})
 }
 
 func (s *HostService) SetHostGroupEnable(groupId string, enable bool) error {
@@ -378,7 +381,10 @@ func (s *HostService) DeleteHostsGroup(groupIds []string) error {
 	if len(groupIds) == 0 {
 		return nil
 	}
-	return database.GetDB().Where("group_id IN ?", groupIds).Delete(&model.Host{}).Error
+	return database.GetDB().Transaction(func(tx *gorm.DB) error {
+		_, err := database.DeleteHosts(tx, "group_id IN ?", groupIds)
+		return err
+	})
 }
 
 func (s *HostService) ReorderHostGroups(groupIds []string) error {

internal/web/service/inbound.go

@@ -1665,7 +1665,7 @@ func (s *InboundService) delInbound(id int) (bool, func(), error) {
 		if err := tx.Delete(model.Inbound{}, id).Error; err != nil {
 			return err
 		}
-		if err := tx.Where("inbound_id = ?", id).Delete(&model.Host{}).Error; err != nil {
+		if _, err := database.DeleteHosts(tx, "inbound_id = ?", id); err != nil {
 			return err
 		}
 		// Drop the deleted inbound from any sub-balancer that selects it; a

internal/web/service/inbound_traffic.go

@@ -964,7 +964,7 @@ func (s *InboundService) DelDepletedClients(id int) (err error) {
 				if err := s.clientService.DetachInbound(tx, inbound.Id); err != nil {
 					return err
 				}
-				if err := tx.Where("inbound_id = ?", inbound.Id).Delete(&model.Host{}).Error; err != nil {
+				if _, err := database.DeleteHosts(tx, "inbound_id = ?", inbound.Id); err != nil {
 					return err
 				}
 				if err := tx.Delete(model.Inbound{}, inbound.Id).Error; err != nil {