Github Agentic Workflows

This is the comprehensive skill for working with GitHub's new agentic workflow system, the markdown-based automation that compiles down to Actions YAML but lets AI agents make runtime decisions. It walks you through the full lifecycle: authoring workflows with proper frontmatter and safe outputs, setting up Copilot authentication, running gh aw compile and trial commands, and debugging common pitfalls like concurrency groups in matrix jobs or secret scope issues. The procedures are opinionated and specific, like preferring safe outputs over direct write permissions and warning you that runtime placeholders don't reach the agent body the way you'd expect. Use this when you're building or maintaining GH-AW automation, not standard deterministic Actions.