t3code was added to the agent matrix but its Dockerfile was never created.
Users running `spawn t3code <cloud> --beta docker`, `--beta sandbox`, or in
the fast_provision experiment group hit a runtime failure because the image
ghcr.io/openrouterteam/spawn-t3code:latest does not exist.
Follows the same pattern as pi.Dockerfile: ubuntu:24.04, Node.js 22 via n,
`npm install -g t3`.
The .github/workflows/docker.yml matrix update is tracked in #3418 (requires
human review — off-limits for automated agents).
Agent: refactor/code-health
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
