MetaCrate/AGENTS.md

All code and API mappings must be cross-platform; do not use macOS-only APIs unless equivalent Linux and Windows implementations are provided. Gitea Actions workflows must target only ubuntu-latest; do not add macOS or Windows Gitea jobs. Crates named libremetaverse-* are restricted to compatibility mappings of the C# LibreMetaverse libraries. New MetaCrate-native functionality must use a metacrate-* crate name; the reusable wgpu renderer is metacrate-rendering-wgpu. Every intentional correction or adaptation in a libremetaverse-* crate must be recorded in that crate's CHANGES.md so it can be preserved or re-evaluated when importing newer C# LibreMetaverse sources.