fixed gorm shema for correct deletion and many2many relation beetween users and devices

server/internal/handlers/users.go

@@ -106,12 +106,10 @@ func (h *UsersHandler) Delete(c *gin.Context) {
 		return
 	}
 	var u models.User
-	if err := h.db.Preload("Devices").First(&u, id).Error; err != nil {
+	if err := h.db.First(&u, id).Error; err != nil {
 		c.JSON(http.StatusNotFound, gin.H{"error": "user not found"})
 		return
 	}
-	// optional safeguard: prevent self-delete; uncomment if desired
-	// if ClaimUserID(MustClaims(c)) == u.ID { c.JSON(http.StatusBadRequest, gin.H{"error":"cannot delete yourself"}); return }
 	if err := h.db.Transaction(func(tx *gorm.DB) error {
 		if err := tx.Model(&u).Association("Devices").Clear(); err != nil {
 			return err