Split a module that holds most of the code, even when small modules exist #31

Context

The module view splits the largest module by directories only when fewer than two modules result. A repository whose code sits in one package plus a small scripts/ directory (or a root config file) yields two modules, so nothing is split: one module holds almost all the code and its cohesion says nothing. This is the "single-package CLI repo" case from the survey on #15.

Goal

A module that holds most of the universe is split into its directories even when other small modules exist.

Acceptance criteria

• When one module holds more than a documented share of the universe files (for example 80 %), it is split with the directory fallback rule.
• A detection test with one package of 50 files plus scripts/ (3 files) yields modules inside the package.
• GLOSSARY.md describes the rule.

References

• packages/engine/src/modules/detect.ts, packages/engine/src/modules/directory-split.ts
• Related: Show module cohesion and cross-module coupling, aware of workspace packages #15