* feat(import): add customer and supplier parsing functionality
- Implemented customer file parsing in `lib/import/customers/parser.ts` with support for Excel and CSV formats.
- Created types for detected customer columns and parsed customer rows in `lib/import/customers/types.ts`.
- Added tests for customer classification logic in `lib/import/shared/__tests__/classify.test.ts`.
- Developed classification functions for customers and suppliers in `lib/import/shared/classify.ts`.
- Introduced shared column utility functions in `lib/import/shared/column-utils.ts`.
- Implemented supplier file parsing in `lib/import/suppliers/parser.ts` with validation for various fields.
- Created types for detected supplier columns and parsed supplier rows in `lib/import/suppliers/types.ts`.
- Added tests for supplier column detection and parsing in `lib/import/suppliers/__tests__/column-detector.test.ts` and `lib/import/suppliers/__tests__/parser.test.ts`.
* fix(labels): update 'Svenskt företag' to 'Svenskt företag eller organisation' for clarity
* feat(import): refactor encoding handling for Swedish files and add tests for character preservation
* feat(recapt): implement clearRecaptIdentity function and integrate into logout flow
* feat(bookkeeping): implement copy functionality and next voucher sequence retrieval
* feat(import): enhance customer and supplier import functionality with normalization and event handling
Mattsson