Major refactor of commerce and Stripe integration

Refactored commerce models to support refunds, invoices, and improved carrier/payment logic. Added new serializers and viewsets for products, categories, images, discount codes, and refunds. Introduced Stripe client integration and removed legacy Stripe admin/model code. Updated Dockerfile for PDF generation dependencies. Removed obsolete migration files and updated configuration app initialization. Added invoice template and tasks for order cleanup.

backend/thirdparty/downloader/migrations/0001_initial.py

@@ -1,30 +0,0 @@
-# Generated by Django 5.2.7 on 2025-10-29 14:53
-
-from django.db import migrations, models
-
-
-class Migration(migrations.Migration):
-
-    initial = True
-
-    dependencies = [
-    ]
-
-    operations = [
-        migrations.CreateModel(
-            name='DownloaderRecord',
-            fields=[
-                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ('is_deleted', models.BooleanField(default=False)),
-                ('deleted_at', models.DateTimeField(blank=True, null=True)),
-                ('url', models.URLField()),
-                ('download_time', models.DateTimeField(auto_now_add=True)),
-                ('format', models.CharField(max_length=50)),
-                ('length_of_media', models.IntegerField(help_text='Length of media in seconds')),
-                ('file_size', models.BigIntegerField(help_text='File size in bytes')),
-            ],
-            options={
-                'abstract': False,
-            },
-        ),
-    ]