Replaced `float` with `Decimal` for monetary calculations to prevent precision loss and enhance accuracy. Updated related models, serializers, and utility functions accordingly.
Fixes: 1) Remove deprecated Jazzmin configuration and replace with unfold dependencies; 2) Update DRF API title to use new PROJECT_NAME; 3) Fix import order and remove unused imports in core/viewsets.py;
Extra: 1) Add PROJECT_NAME to base settings; 2) Update INSTALLED_APPS to include unfold-related apps; 3) Clean up unused config references.
Fixes: 1) Add missing import for `settings` in multiple modules;
Extra: 1) Remove unused `SerializerMethodField` from serializers; 2) Update `RELEASE_DATE` to align with new version; 3) General cleanup and consistency adjustments.
