//! `navigator.rs`'s test suite, split by theme. `support` carries
//! fixtures/harnesses shared by more than one theme; every other child
//! module is one theme, split along the original `#[cfg(test)] mod tests`
//! section-divider comments (stack/ops, back-request routing, page
//! transitions, edge-swipe gesture, page visibility, route-state
//! observable, and root-overlay-host semantics).