Add/csv import options (#420)

* 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

components/dashboard/DashboardNav.tsx

@@ -33,6 +33,7 @@ import { resolveIcon } from '@/lib/extensions/icon-resolver'
 import { SupportLink } from '@/components/ui/support-link'
 import CompanySwitcher from '@/components/dashboard/CompanySwitcher'
 import { useCompany } from '@/contexts/CompanyContext'
+import { clearRecaptIdentity } from '@/lib/recapt'
 import type { EntityType } from '@/types'
 
 interface ExtensionNavItem {
@@ -127,6 +128,7 @@ export default function DashboardNav({ companyName: _companyName, entityType, un
   }
 
   const handleLogout = async () => {
+    clearRecaptIdentity()
     await supabase.auth.signOut()
     router.push(isSandbox ? '/sandbox' : '/login')
   }