fix(plan): respect explicit COLI_CUDA_MTP=1 - skip the planner's DRAFT=0 export (opt-in was silently inert) - #470

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-node@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/