The Export and Import buttons in CompanySettings used plain <a href>
anchors which bypass the router's company-prefix wrapper. The links
resolved to /company/export and /company/import instead of
/:prefix/company/export, showing a 'Company not found' error.
Replace both <a href> elements with <Link to> from @/lib/router, which
calls applyCompanyPrefix under the hood and correctly resolves to
/:prefix/company/{export,import} regardless of which company is active.
Fixes: #2910