PrivateresolveResolve the currently selected actual dimension index, or -1
when no dim is selectable. Centralizes the
selectedDimension → dims → navigableDims[i] lookup so the
bindings can read it without re-implementing the SimpleDims
indirection.
PrivatetogglePrivatejumpPrivateadjust
Register the five animation-shortcut bindings on the
NAVIGATIONcontext.registerAllKeyBindings()calls this once during InputHandler startup; the handlers decline until a scene provides a selected dimension and animation manager.