python:3.12-slim lacks node, so actions/checkout@v4 fails.
Use manual git clone with Gitea environment variables instead.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Replace actions/setup-python@v5 (skipped by act runner) with
python:3.12-slim container images so Python is available directly.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>