The favorites, watchlist, and history list endpoints returned only
{items: [...]} with no has_more field. Clients gate infinite-scroll
pagination on has_more (absent -> false), so they stopped after the first
page — users saw only the first ~page of favorites and adding one pushed
the oldest off the visible window (reported: Silo-Server/silo-android#56,
affects both phone and TV). The catalog/browse endpoint already returns
has_more; these three were the odd ones out.
Add has_more to itemsListResponse, computed from the RAW store page size
(== limit), not the resolved item count — resolveItems drops
catalog-missing entries and watchlist filters hidden series, so basing it
on the returned length would make a full page look final. Backward
compatible (additive field).
