When SwiftUI navigation is broken and the standard debugging guide didn't fix it, this is the diagnostic deep dive. It's referenced directly from the main axiom-swiftui skill's quick reference table under "Navigation still broken after debugging." Think of it as the second tier escalation: nav.md gets you through the common NavigationStack pitfalls, but if you're still seeing phantom pushes, state restoration failures, or deep linking that won't resolve, nav-diag.md has the advanced patterns. It sits between the introductory navigation guide and the full API reference, focused purely on "I followed the rules and it's still wrong" scenarios.
npx skills add https://github.com/charleswiltgen/axiom --skill axiom-swiftui-nav-diag