refactor: remove redundant Begin() calls after NewSession auto-begins

Since NewSession() now auto-begins a transaction, explicit Begin()
calls are redundant (xorm's Begin() is a no-op when already in a
transaction). Removing them reduces confusion.

Special case: user_delete.go's loop previously called Begin/Commit
per user on a shared session. Restructured to create a new session
per user deletion so each gets its own transaction.

pkg/cmd/repair_file_mime_types.go

@@ -44,14 +44,6 @@ on file creation. Only files with an empty or NULL mime column are affected.`,
 		s := db.NewSession()
 		defer s.Close()
 
-		if err := s.Begin(); err != nil {
-			log.Errorf("Failed to start transaction: %s", err)
-			return
-		}
-		defer func() {
-			_ = s.Rollback()
-		}()
-
 		result, err := files.RepairFileMimeTypes(s)
 		if err != nil {
 			log.Errorf("Failed to repair file MIME types: %s", err)

pkg/cmd/repair_task_positions.go

@@ -55,15 +55,6 @@ Use --dry-run to preview what would be fixed without making changes.`,
 
 		if dryRun {
 			log.Infof("Running in dry-run mode - no changes will be made")
-		} else {
-			if err := s.Begin(); err != nil {
-				log.Errorf("Failed to start transaction: %s", err)
-				return
-			}
-			defer func() {
-				// Rollback is a no-op if commit already succeeded
-				_ = s.Rollback()
-			}()
 		}
 
 		result, err := models.RepairTaskPositions(s, dryRun)

pkg/cmd/user.go

@@ -369,10 +369,6 @@ var userDeleteCmd = &cobra.Command{
 		s := db.NewSession()
 		defer s.Close()
 
-		if err := s.Begin(); err != nil {
-			log.Fatalf("Count not start transaction: %s", err)
-		}
-
 		u := getUserFromArg(s, args[0])
 
 		if userFlagDeleteNow {

pkg/models/listeners.go

@@ -1199,11 +1199,6 @@ func (l *CleanupTaskAssignmentsAfterTeamRemoval) Handle(msg *message.Message) (e
 		return nil
 	}
 
-	err = s.Begin()
-	if err != nil {
-		return err
-	}
-
 	err = cleanupTaskMembersAfterTeamRemoval(s, event.Team.ID, event.Member.ID)
 	if err != nil {
 		_ = s.Rollback()
@@ -1263,10 +1258,6 @@ func (s *HandleUserDataExport) Handle(msg *message.Message) (err error) {
 
 	sess := db.NewSession()
 	defer sess.Close()
-	err = sess.Begin()
-	if err != nil {
-		return
-	}
 
 	err = ExportUserData(sess, event.User)
 	if err != nil {
@@ -1276,8 +1267,7 @@ func (s *HandleUserDataExport) Handle(msg *message.Message) (err error) {
 
 	log.Debugf("Done exporting user data for user %d...", event.User.ID)
 
-	err = sess.Commit()
-	return err
+	return sess.Commit()
 }
 
 type MarkTaskUnreadOnComment struct {
@@ -1297,11 +1287,6 @@ func (s *MarkTaskUnreadOnComment) Handle(msg *message.Message) (err error) {
 	sess := db.NewSession()
 	defer sess.Close()
 
-	err = sess.Begin()
-	if err != nil {
-		return err
-	}
-
 	project, err := GetProjectSimpleByID(sess, event.Task.ProjectID)
 	if err != nil {
 		_ = sess.Rollback()

pkg/models/typesense.go

@@ -536,7 +536,6 @@ func SyncUpdatedTasksIntoTypesense() (err error) {
 	tasks := make(map[int64]*Task)
 
 	s := db.NewSession()
-	_ = s.Begin()
 	defer s.Close()
 
 	lastSync := &TypesenseSync{}

pkg/models/user_delete.go

@@ -65,26 +65,24 @@ func deleteUsers() {
 			continue
 		}
 
-		err = s.Begin()
-		if err != nil {
-			log.Errorf("Could not start transaction: %s", err)
-			return
-		}
+		func() {
+			us := db.NewSession()
+			defer us.Close()
 
-		err = DeleteUser(s, u)
-		if err != nil {
-			_ = s.Rollback()
-			log.Errorf("Could not delete u %d: %s", u.ID, err)
-			return
-		}
+			err = DeleteUser(us, u)
+			if err != nil {
+				_ = us.Rollback()
+				log.Errorf("Could not delete u %d: %s", u.ID, err)
+				return
+			}
 
-		log.Debugf("Deleted user %d", u.ID)
+			log.Debugf("Deleted user %d", u.ID)
 
-		err = s.Commit()
-		if err != nil {
-			log.Errorf("Could not commit transaction: %s", err)
-			return
-		}
+			err = us.Commit()
+			if err != nil {
+				log.Errorf("Could not commit transaction: %s", err)
+			}
+		}()
 	}
 }
 

pkg/routes/api/v1/user_deletion.go

@@ -50,11 +50,6 @@ func UserRequestDeletion(c *echo.Context) error {
 	s := db.NewSession()
 	defer s.Close()
 
-	err := s.Begin()
-	if err != nil {
-		return err
-	}
-
 	u, err := user.GetCurrentUserFromDB(s, c)
 	if err != nil {
 		_ = s.Rollback()
@@ -119,11 +114,6 @@ func UserConfirmDeletion(c *echo.Context) error {
 	s := db.NewSession()
 	defer s.Close()
 
-	err = s.Begin()
-	if err != nil {
-		return err
-	}
-
 	u, err := user.GetCurrentUserFromDB(s, c)
 	if err != nil {
 		_ = s.Rollback()
@@ -161,11 +151,6 @@ func UserCancelDeletion(c *echo.Context) error {
 	s := db.NewSession()
 	defer s.Close()
 
-	err := s.Begin()
-	if err != nil {
-		return err
-	}
-
 	u, err := user.GetCurrentUserFromDB(s, c)
 	if err != nil {
 		_ = s.Rollback()

pkg/routes/api/v1/user_export.go

@@ -34,11 +34,6 @@ func checkExportRequest(c *echo.Context) (s *xorm.Session, u *user.User, err err
 	s = db.NewSession()
 	defer s.Close()
 
-	err = s.Begin()
-	if err != nil {
-		return nil, nil, err
-	}
-
 	u, err = user.GetCurrentUserFromDB(s, c)
 	if err != nil {
 		_ = s.Rollback()