Three-part effort:
1. Rootless refactor: removes docker/binary modes, unifies to rootless Docker with per-runner system users
2. Auto-merge fix: fix status check context mismatch in branch protection, add retry/wait logic to auto_merge.py
3. Molecule platform matrix: add OS platform matrix to CI (ubuntu-2204, ubuntu-2404, debian-12, archlinux), distribute (scenario, platform) pairs across runners
4. Cross-runner molecule cancellation via Gitea API polling
5. Sequential molecule execution within each runner
6. Fix idempotence, systemd user bus, and Arch Linux package name issues
Generated with [Devin](https://devin.ai)
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
emil