Enhanced quarterly confirmation system with approval workflow and export improvements

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

app/core/settings.py

@@ -36,6 +36,9 @@ INSTALLED_APPS = [
     "rest_framework",
     "stiftung",
 ]
+# Add this to app/core/settings.py
+SESSION_COOKIE_NAME = 'stiftung_sessionid'  # Different from default 'sessionid'
+
 
 MIDDLEWARE = [
     "django.middleware.security.SecurityMiddleware",
@@ -120,10 +123,6 @@ GRAMPS_STIFTER_IDS = os.environ.get("GRAMPS_STIFTER_IDS", "")  # comma-separated
 GRAMPS_USERNAME = os.environ.get("GRAMPS_USERNAME", "")
 GRAMPS_PASSWORD = os.environ.get("GRAMPS_PASSWORD", "")
 
-# Session Configuration
-SESSION_COOKIE_NAME = os.environ.get("SESSION_COOKIE_NAME") or "stiftung_sessionid"
-CSRF_COOKIE_NAME = os.environ.get("CSRF_COOKIE_NAME") or "stiftung_csrftoken"
-
 # HTTPS Security Settings (production)
 if not DEBUG:
     SECURE_SSL_REDIRECT = True