Fix listing filter scope + Home Screen Sections duplicates

[EclipseKnight]

I’m combining this into one PR so it’s easier to review.

I traced the main issue to the filter guard in GelatoItemRepository.ApplyFilters (after the IsSingleItemList() change around 1cb8d57).

IsSingleItemList() depends on ids in the HTTP query, but some internal query paths don’t pass ids, so those requests were getting filtered in places they shouldn’t. That caused slow loading/timeouts.

I changed the guard to:

• use ctx.IsApiListing()
• skip true single-item internal queries with filter.ItemIds is { Length: 1 }

I also added GetSectionContent to BaseItemListActionNames in Common.cs.

Reason for that:

• Home Screen Sections latest rows come through HomeScreenController.GetSectionContent
• if that action isn’t treated as listing, Gelato’s normal listing filter path doesn’t run there
• once it is treated as listing, existing ExcludeTags = [GelatoManager.StreamTag] applies and the duplicate stream variants are filtered out in those rows

I’m using this PR as the single place for both fixes.

[lostb1t]

Do you know which queries, how they look like? so we can understand what exactly causes the slowdown