Add shopping cart and product review features

Introduces Cart and CartItem models, admin, serializers, and API endpoints for shopping cart management for both authenticated and anonymous users. Adds Review model, serializers, and endpoints for product reviews, including public creation and retrieval. Updates ProductImage ordering, enhances order save logic with notification, and improves product and order endpoints with new actions and filters. Includes related migrations for commerce, configuration, social chat, and Deutsche Post integration.

backend/commerce/migrations/0002_alter_productimage_options_carrier_deutschepost_and_more.py

@@ -0,0 +1,83 @@
+# Generated by Django 5.2.7 on 2026-01-17 01:37
+
+import django.core.validators
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('commerce', '0001_initial'),
+        ('deutschepost', '0001_initial'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='productimage',
+            options={'ordering': ['order', '-is_main', 'id']},
+        ),
+        migrations.AddField(
+            model_name='carrier',
+            name='deutschepost',
+            field=models.ManyToManyField(blank=True, related_name='carriers', to='deutschepost.deutschepostorder'),
+        ),
+        migrations.AddField(
+            model_name='productimage',
+            name='order',
+            field=models.PositiveIntegerField(default=0, help_text='Display order (lower numbers first)'),
+        ),
+        migrations.AlterField(
+            model_name='carrier',
+            name='shipping_method',
+            field=models.CharField(choices=[('packeta', 'cz#Zásilkovna'), ('deutschepost', 'cz#Deutsche Post'), ('store', 'cz#Osobní odběr')], default='store', max_length=20),
+        ),
+        migrations.AlterField(
+            model_name='product',
+            name='variants',
+            field=models.ManyToManyField(blank=True, help_text='Symetrické varianty produktu: pokud přidáte variantu A → B, Django automaticky přidá i variantu B → A. Všechny varianty jsou rovnocenné a zobrazí se vzájemně.', to='commerce.product'),
+        ),
+        migrations.CreateModel(
+            name='Cart',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('session_key', models.CharField(blank=True, help_text='Session key for anonymous users', max_length=40, null=True)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('updated_at', models.DateTimeField(auto_now=True)),
+                ('user', models.OneToOneField(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='cart', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'verbose_name': 'Cart',
+                'verbose_name_plural': 'Carts',
+            },
+        ),
+        migrations.CreateModel(
+            name='Review',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('rating', models.PositiveIntegerField(validators=[django.core.validators.MinValueValidator(1), django.core.validators.MaxValueValidator(5)])),
+                ('comment', models.TextField(blank=True)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('updated_at', models.DateTimeField(auto_now=True)),
+                ('product', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='reviews', to='commerce.product')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='reviews', to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='CartItem',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('quantity', models.PositiveIntegerField(default=1)),
+                ('added_at', models.DateTimeField(auto_now_add=True)),
+                ('cart', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='items', to='commerce.cart')),
+                ('product', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='commerce.product')),
+            ],
+            options={
+                'verbose_name': 'Cart Item',
+                'verbose_name_plural': 'Cart Items',
+                'unique_together': {('cart', 'product')},
+            },
+        ),
+    ]