feat: add initial Django domain models

backend/checkins/migrations/0001_initial.py

@@ -0,0 +1,54 @@
+# Generated by Django 5.2.3 on 2026-04-28
+
+import django.db.models.deletion
+import django.utils.timezone
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    initial = True
+
+    dependencies = [
+        ("bookings", "0001_initial"),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="CheckIn",
+            fields=[
+                ("id", models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")),
+                ("checked_in_at", models.DateTimeField(default=django.utils.timezone.now)),
+                (
+                    "source",
+                    models.CharField(choices=[("qr_scan", "QR scan"), ("manual", "Manual")], default="qr_scan", max_length=20),
+                ),
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ("updated_at", models.DateTimeField(auto_now=True)),
+                (
+                    "checked_in_by",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="checkins",
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+                (
+                    "reservation",
+                    models.OneToOneField(
+                        on_delete=django.db.models.deletion.PROTECT,
+                        related_name="check_in",
+                        to="bookings.reservation",
+                    ),
+                ),
+            ],
+            options={
+                "ordering": ["-checked_in_at"],
+                "indexes": [
+                    models.Index(fields=["checked_in_at"], name="checkins_ch_checked_761e33_idx"),
+                    models.Index(fields=["checked_in_by"], name="checkins_ch_checked_becaae_idx"),
+                ],
+            },
+        ),
+    ]