fix: Ensure unique slug generation for SubCategoryModel

backend/product/models.py

@@ -99,8 +99,22 @@ class SubCategoryModel(models.Model):
         return self.name
 
     def save(self, *args, **kwargs):
+        # Ensure slug is present and unique. If a slug (auto or custom) would
+        # collide with an existing product, append a numeric suffix.
         if not self.slug:
-            self.slug = slugify(self.name, allow_unicode=True)
+            base_slug = slugify(self.name, allow_unicode=True)
+        else:
+            # Normalize a provided slug
+            base_slug = slugify(self.slug, allow_unicode=True)
+
+        slug_candidate = base_slug
+        counter = 1
+        # Exclude self.pk to allow updating the same instance
+        while ProductModel.objects.filter(slug=slug_candidate).exclude(pk=self.pk).exists():
+            slug_candidate = f"{base_slug}-{counter}"
+            counter += 1
+
+        self.slug = slug_candidate
         super().save(*args, **kwargs)