Runs scripts/module_depgraph.py --check on every push and PR. It fails when a module gains an #include pointing up the layering, outside the 16 back-edges already whitelisted in the script. No build or toolchain needed, so it reports before the platform jobs finish. This is step S1 of docs/dev/模块编排与裁剪架构.md. Co-authored-by: 西风逍遥游 <sunxfancy@gmail.com>