Function apply_navigation 

pub fn apply_navigation(
    store: ResMut<'_, PropertyStore>,
    registry: Option<Res<'_, PageRegistry>>,
    history: ResMut<'_, RouteHistory>,
    last: Local<'_, Option<String>>,
)

The single navigation resolver. Reads the reserved request signal (written by every surface via lumen_core::nav::request), resolves the target by longest existing-file prefix, updates the reserved route.path / route.segment cells, and maintains the in-memory history stack.