feat(Foundations): pilot and probabilistic column detectors for one hierarchy stage - #1696

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. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Not declared at the PR head: `rank_k`, `rank_j`, `G_i`, `R_i`, `U_i`, `Ê_i`, `r_j`, `D₀`. Advisory only; see the job summary.