#resource

The [GameResource("Name","ext","desc")] attribute on a GameResource subclass now raises CS0618 obsolete. It is a warning, so a green dotnet build hides it unless the project treats warnings as errors. Switch to [AssetType] with named properties. The type still derives from GameResource, still writes an .ext file, and is still found by ResourceLibrary.GetAll<T>(). Only the declaring attribute changes, and the old Icon argument has no replacement.

A project resource type that claims a file extension the engine already owns can lose a registration race, with no error. The losing type's ResourceLibrary.GetAll returns empty and files deserialize as the engine type instead. Which side wins is decided per editor launch. Audit the extension with asset_types before you commit to it.