Add management command to populate Product slugs

Introduce a Django management command to populate the `slug` field for Product instances where it is null. The command processes products in batches, handles errors gracefully, and logs issues for troubleshooting.

core/management/commands/populate_slugs.py

@@ -0,0 +1,31 @@
+import logging
+
+from django.core.management.base import BaseCommand
+from django.db import transaction
+from core.models import Product
+
+logger = logging.getLogger(__name__)
+
+
+class Command(BaseCommand):
+    help = "Populate slug field for all Product instances"
+
+    def handle(self, *args, **options):
+        qs = Product.objects.filter(slug__isnull=True)
+        total = qs.count()
+        self.stdout.write(f"Starting slug population for {total} products")
+
+        for idx, product in enumerate(qs.iterator(), start=1):
+            try:
+                product.slug = None
+                with transaction.atomic():
+                    product.save(update_fields=["slug"])
+
+                self.stdout.write(
+                    self.style.SUCCESS(f"[{idx}/{total}] (Product ID: {product.pk}) slug set to '{product.slug}'")
+                )
+            except Exception as e:
+                logger.exception(f"Product {product.pk}: slug population failed")
+                self.stderr.write(self.style.ERROR(f"[{idx}/{total}] (Product ID: {product.pk}) ERROR: {e}"))
+
+        self.stdout.write(self.style.SUCCESS("Slug population complete."))