feat: Use choices and fix bug where default was not honored

src/fellchensammlung/migrations/0040_alter_rescueorganization_allows_using_materials.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.1.4 on 2025-03-20 23:27
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('fellchensammlung', '0039_alter_rescueorganization_last_checked'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='rescueorganization',
+            name='allows_using_materials',
+            field=models.CharField(choices=[('allowed', 'Usage allowed'), ('requested', 'Usage requested'), ('denied', 'Usage denied'), ('other', "It's complicated"), ('not_asked', 'Not asked')], default='not_asked', max_length=200, verbose_name='Erlaubt Nutzung von Inhalten'),
+        ),
+    ]