Add Builds/levelization/levelization.py for fast local iteration and semantic comparison against canonical shell output via --compare-to.
Keep Builds/levelization/levelization.sh as canonical path, and update levelization workflow to fail if python output diverges from shell-generated results.
Also harden interactive-shell detection in levelization.sh for portability and document local usage in README.
* Markdown explanation of what levelization is, the intended levels, as
well as the process used to determine dependencies
* Shell script finds all dependencies, groups them, and finds cyclic
dependencies and maps out non-cyclic dependencies.
* Github job to run the script and fail if anything changes. Should
catch introduction of new dependencies and new problems. Will also
detect changes if problems or dependencies are removed.
