Features added:
- New getCA3LineDetails() method in DeclarationTVA class
- New declarationtva_line_details.php page for detailed view
- All CA-3 line codes are now clickable in declaration view
- Detailed breakdown shows:
* Account codes and labels
* Base amounts, VAT amounts, total amounts
* Mapping types (A1, 08_BASE, 08_VAT, etc.)
* Calculated totals vs account totals
- Added comprehensive translations for detailed view
- Navigation breadcrumbs and back buttons
- Professional styling with Dolibarr UI components
This provides complete transparency into which accounts contribute to each CA-3 line without touching the calculation logic.