List draft content items for a social account, optionally narrowed to one category

Paginated. page is zero-based and defaults to 0; size defaults to 50 and is clamped to a maximum of 100. Out-of-range values are clamped rather than rejected, and the response echoes the applied page and size alongside totalElements, totalPages and hasNext. Requesting a page past the last one returns an empty items array with the real totals, not an error.