Features added:
- ✅ Fixed quarterly confirmation approval system with URL pattern
- ✅ Added re-approval and status reset functionality for quarterly confirmations
- ✅ Synchronized quarterly approval status with support payment system
- ✅ Enhanced Destinataer export with missing fields (anrede, titel, mobil)
- ✅ Added quarterly confirmation data and documents to export system
- ✅ Fixed address field display issues in destinataer template
- ✅ Added quarterly statistics dashboard to support payment lists
- ✅ Implemented duplicate support payment prevention and cleanup
- ✅ Added visual indicators for quarterly-linked support payments
Technical improvements:
- Enhanced create_quarterly_support_payment() with duplicate detection
- Added get_related_support_payment() method to VierteljahresNachweis model
- Improved quarterly confirmation workflow with proper status transitions
- Added computed address property to Destinataer model
- Fixed template field mismatches (anrede, titel, mobil vs strasse, plz, ort)
- Enhanced backup system with operation tracking and cancellation
Workflow enhancements:
- Quarterly confirmations now properly sync with support payments
- Single support payment per destinataer per quarter (no duplicates)
- Approval button works for both eingereicht and geprueft status
- Reset functionality allows workflow restart
- Export includes complete quarterly data with uploaded documents
- Enhanced 'Alle Unterstützungen' view with IBAN and Verwendungszweck columns for better payment tracking
- Updated export functions to handle both legacy 'selected_fields' and new 'fields' parameters
- Added IBAN and Verwendungszweck to default export field selections
- Improved destinataer list UI by adding Status column and removing obsolete study proof field
- Fixed infinite growing animation bug in 'Größen der Grundstücke (Top 30)' chart by replacing Chart.js with CSS-based implementation
- Removed Bootstrap h-100 class conflicts that caused chart resize loops
