The options stored in options-ref is a delay (lazy value). In
on-token-key-down, it was passed raw to next-focus-index without being
dereferenced first, causing count to be called on a JS object that does
not implement ICounted.
Fix: dereference the delay in on-token-key-down (matching the existing
pattern in on-key-down), and make next-focus-index itself also handle
delays defensively. Add unit tests covering the delay case.
