Add multi-image compositions, docker setup, tests, and docs

- Add CompositionImage model with multi-image upload and main image flag
- Add composition endpoints: add-images, set-main-image, delete image, by-created-at filter
- Make contact-us by_category public
- Add 24 API tests covering all endpoints
- Add Dockerfile, docker-compose, entrypoint and docker docs
- Add Persian API docs and update README and Postman collection

Co-authored-by: Cursor <cursoragent@cursor.com>

api/migrations/0002_composition_images.py

@@ -0,0 +1,33 @@
+# Generated by Django 4.2.7 on 2026-06-23 14:12
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='CompositionImage',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('image', models.ImageField(upload_to='compositions/', verbose_name='تصویر')),
+                ('is_main', models.BooleanField(default=False, verbose_name='تصویر اصلی')),
+                ('created_at', models.DateTimeField(auto_now_add=True, verbose_name='تاریخ ایجاد')),
+                ('composition', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='images', to='api.composition', verbose_name='ترکیب')),
+            ],
+            options={
+                'verbose_name': 'تصویر ترکیب',
+                'verbose_name_plural': 'تصاویر ترکیب',
+                'ordering': ['-is_main', '-created_at'],
+            },
+        ),
+        migrations.AddConstraint(
+            model_name='compositionimage',
+            constraint=models.UniqueConstraint(condition=models.Q(('is_main', True)), fields=('composition',), name='unique_main_image_per_composition'),
+        ),
+    ]