- | Root | Provider and control expose horizontal listbox semantics. |
- | Input | Input is a combobox with autocomplete and active descendant support. |
- | Items | Tags are options with active/inactive state and delete triggers. |
+ | Root | The control is a single-row layout grid (APG); the provider carries no role. |
+ | Input | Plain text field in its own cell — no combobox, because there is no popup. |
+ | Items | Tags are grid cells with active/inactive state; their delete button stays operable. |
| Keyboard | Enter adds; Backspace deletes previous when input is empty; arrows navigate tags. |
| Readonly | Readonly blocks add/remove while keeping existing tags readable. |