- Implemented `InvoicingPeriodPaginationTest` for testing period pagination modes, normalization of options, search functionality, and visibility filters.
- Added comprehensive tests to validate scenarios such as active period views, exact counts, and customer-card level search.
- Improved cURL timeout settings with `CURLOPT_CONNECTTIMEOUT` and `CURLOPT_TIMEOUT` adjustments.
- Introduced and documented helper classes/methods for local caching, pagination response structure, and customer name retrieval.