GitHub Agentic Workflows goes GA: write Actions automations in Markdown and let a coding agent run them

Announced at Universe on Oct 28, you describe tasks like issue triage, CI failure analysis or test writing in a Markdown file, and gh aw compiles it to standard Actions YAML powered by Copilot or your own coding agent, running read-only by default in a sandboxed container with a threat-detection job checking proposed changes. GA adds self-hosted ARC runners, per-workflow model choice and routing, micro-VM isolation, and gh aw forecast for estimating AI credit spend.