Enhance Destinataer functionality: inline editing and improved list view

- Add inline edit mode to destinataer detail view with AJAX save/cancel
- Fix form validation by aligning select choices with model definitions
- Update Destinataer model to make familienzweig and berufsgruppe optional
- Fix StiftungsKonto integration in forms and views
- Redesign destinataer list view with new column layout:
  * Vorname, Nachname, E-Mail, Vierteljährlicher Betrag
  * Letzter Studiennachweis, Unterstützung bestätigt, Aktionen
- Improve form styling and user experience
- Add proper field validation and error handling
- Enhance UI with better badges, icons, and formatting

app/stiftung/migrations/0029_alter_destinataer_berufsgruppe_and_more.py

@@ -0,0 +1,23 @@
+# Generated by Django 5.0.6 on 2025-09-19 21:24
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stiftung', '0028_alter_helpbox_page_key'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='destinataer',
+            name='berufsgruppe',
+            field=models.CharField(blank=True, choices=[('student', 'Student/Studentin'), ('wissenschaftler', 'Wissenschaftler/in'), ('künstler', 'Künstler/in'), ('sozialarbeiter', 'Sozialarbeiter/in'), ('umweltschützer', 'Umweltschützer/in'), ('andere', 'Andere')], max_length=20, null=True, verbose_name='Berufsgruppe'),
+        ),
+        migrations.AlterField(
+            model_name='destinataer',
+            name='familienzweig',
+            field=models.CharField(blank=True, choices=[('hauptzweig', 'Hauptzweig'), ('nebenzweig', 'Nebenzweig'), ('verwandt', 'Verwandt'), ('anderer', 'Anderer')], max_length=100, null=True),
+        ),
+    ]