Self-hosted respellion-linux runner not required — Gitea's hosted ubuntu-latest runner has Docker + Compose v2 out of the box, so make smoke works without any manual registration step. Updates docs/runbooks/ci.md to reflect the new runner label and removes the act_runner self-hosted setup as the primary path. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>