Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@frontend/components/q`&a/Pagination.tsx:
- Around line 218-239: The hard-coded IDs "qa-page-size-label" and
"qa-page-size-trigger" cause collisions when multiple Pagination components
mount; generate instance-scoped IDs (e.g., with React's useId() or a unique
suffix) and replace the static id attributes on the label and button with those
generated IDs, then update aria-labelledby and any other references
(pageSizeListboxId usage, aria-controls) to use the matching instance-scoped
IDs; ensure the logic around setIsPageSizeOpen, isPageSizeOpen,
pageSizeDropdownRef, and pageSizeListboxId continues to reference the new IDs so
accessibility relationships remain correct.
- Around line 231-289: The page-size dropdown in Pagination.tsx uses
listbox/option roles but lacks keyboard semantics; update the component (using
the qa-page-size-trigger button, isPageSizeOpen/setIsPageSizeOpen,
pageSizeListboxId, pageSizeOptions, onPageSizeChange, pageSize) to implement
proper listbox keyboard interactions: when opening move focus into the listbox
to the selected option (or first option), implement a keydown handler on the
listbox that handles ArrowDown/ArrowUp to move focus (roving tabindex or track
an activeIndex), Home/End to jump to first/last, and Enter/Space to select the
focused option; also keep Escape closing behavior and maintain aria-selected and
aria-activedescendant (or update option tabindex) so screen readers and keyboard
users can navigate correctly, or alternatively replace this custom logic with a
headless/select primitive (e.g., Headless UI/Downshift) that provides the
required semantics.

---

Nitpick comments:
In `@frontend/components/tests/q`&a/pagination.test.tsx:
- Around line 146-148: The test currently only exercises the click flow using
screen.getByLabelText('itemsPerPageAria') and fireEvent.click(...), which misses
keyboard accessibility; update the test to add a keyboard-path regression: use
userEvent (imported as userEvent) to focus the trigger (itemsPerPageAria),
simulate opening the listbox with keyboard (e.g., Enter or Space), navigate to
the "40" option via ArrowDown/ArrowUp or type the option label, activate it with
Enter, and then assert the listbox closed and selection applied; replace or
augment the fireEvent.click calls that target screen.getByRole('option', { name:
'40' }) with userEvent keyboard interactions so focus behavior and keyboard
accessibility of the custom listbox are exercised.