- 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
