v0.2.62 added gcc to Dockerfile.oci. This install builds with --venv, and
build_oci_image.sh uses Dockerfile.oci-venv for that — so the image came out
without a compiler and surya would have gone on falling back exactly as before.
Caught by checking inside the built image rather than trusting the build's exit
code.

The test had the same blind spot: it asserted against one Dockerfile. Both can
ship, so it now checks both, parametrised by file.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0182DhR1eFNPQyGmDrpHbedY