Rewrite all reference files, asset templates, and SKILL.md to use current API patterns (.call(), result.field, T::Enum classes, Tools::Base). Add two new reference files (toolsets, observability) covering tools DSL, event system, and Langfuse integration. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>