Remove lastName field from UserSettings and database

- Removed lastName from UserSettings interface
- Updated UserSettingsForm to remove lastName input field
- Removed lastName from all database operations
- Updated form validation schema to remove lastName validation
- Updated ViewLocationCard to use only firstName for recipient name
- Removed lastName from user settings form state tracking
- Updated Croatian translations to reflect changes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/ui/ViewLocationCard.tsx

@@ -28,7 +28,7 @@ export const ViewLocationCard:FC<ViewLocationCardProps> = ({location, userSettin
         ImePlatitelja: tenantName ?? "",
         AdresaPlatitelja: tenantStreet ?? "",
         SjedistePlatitelja: tenantTown ?? "",
-        Primatelj: (userSettings?.firstName && userSettings?.lastName) ? `${userSettings.firstName} ${userSettings.lastName}` : "",
+        Primatelj: userSettings?.firstName ?? "",
         AdresaPrimatelja: userSettings?.street ?? "",
         SjedistePrimatelja: userSettings?.town ?? "",
         IBAN: userSettings?.iban ?? "",