Modern applications are often assembled from modules. That is good for ownership, deployment boundaries, and keeping large codebases understandable. It also creates a subtle user-experience failure mode: a page can compile, carry a valid route, pass its local tests, and still be effectively absent because no one can discover it from a real entry point.

This is not primarily a visual-design problem. It is an architecture-contract problem.

Routable is not reachable

Imagine an administrative application with pages spread across two modules. The team already has a test that scans routed pages and checks that each one appears in a navigation catalogue. The test is green, so the navigation surface looks covered.

Later, someone discovers that the scan only walks one module. The second route tree was outside its boundary.…