CI / CI (push) Failing after 11s
Replaces the self-hosted astral-uv runner (which had uv pre-installed) with the standard GitHub-hosted ubuntu-latest. Adds back the astral-sh/setup-uv step that was omitted in the self-hosted case. The astral-uv runner was timing out / unreachable from the GitHub Actions side; ubuntu-latest is universally available. Trade-off: ubuntu-latest runners start fresh each run (~30s cold start) and the setup-uv step takes a few seconds to download uv, versus a self-hosted runner that boots in <1s with uv ready. For a single CI job that runs on tag push only, the extra ~10s is not a problem. Co-Authored-By: Claude <noreply@anthropic.com>