pota/use/focus

pota/use/focus covers per-element focus ergonomics as ref functions (autoFocus, selectOnFocus, trapFocus), plus document-level focus state through an emitter (useDocumentFocus / onDocumentFocus) and standalone focus traversal helpers (focusNext / focusPrevious).

Exports

• autoFocus — use:ref: focus on mount
• selectOnFocus — use:ref: select-all on focus
• trapFocus — use:ref: modal-style Tab containment
• focusNext(list?) / focusPrevious(list?) — imperative traversal with wrap-around
• useDocumentFocus() — signal accessor: does the document have focus?
• onDocumentFocus(fn) — callback on focus / blur