feat: BAS data overhaul, currency revaluation, expenses, UI polish, and cleanup

- Update BAS account catalog with comprehensive SRU codes and K2 flags
- Add currency revaluation service with tests and API route
- Add expenses page and account deletion API
- Enhance booking templates with new patterns and improved tests
- Improve transaction categorization with template picker and description matching
- Polish dashboard, onboarding, import, and transaction UIs
- Refactor year-end service for multi-step closing
- Move SRU generator to ne-bilaga, remove standalone SRU export
- Remove unused dev docs, mock data, and extension hooks
- Add invoice delivery note sequences migration

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/api/schemas.ts

@@ -102,6 +102,7 @@ export const JournalEntrySourceTypeSchema = z.enum([
   'supplier_invoice_paid',
   'supplier_invoice_cash_payment',
   'supplier_credit_note',
+  'currency_revaluation',
 ])
 
 export const AccountTypeSchema = z.enum([