feat: Add achievements app with models, admin, and management command for seeding data

backend/server/achievements/migrations/0001_initial.py

@@ -0,0 +1,39 @@
+# Generated by Django 5.0.8 on 2025-02-04 04:34
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Achievement',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=255, unique=True)),
+                ('description', models.TextField()),
+                ('icon', models.ImageField(blank=True, null=True, upload_to='achievements/')),
+                ('condition', models.JSONField()),
+            ],
+        ),
+        migrations.CreateModel(
+            name='UserAchievement',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('earned_at', models.DateTimeField(auto_now_add=True)),
+                ('achievement', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='achievements.achievement')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'unique_together': {('user', 'achievement')},
+            },
+        ),
+    ]