[Tech debt] Improve PerdSelect keyboard navigation

[Perdolique]

Context

PerdSelect currently supports Arrow Up, Arrow Down, Enter, Space, Escape, and Tab commit. It does not yet provide the optional native-select-style navigation covered by the WAI-ARIA select-only combobox and listbox patterns.

This is follow-up technical debt, not a blocker for the current Gear Library integration.

Scope

• Support Home and End navigation across enabled options.
• Support printable-character typeahead, including multi-character matching within a short input window.
• Skip disabled options for all added navigation.
• Keep the active option, aria-activedescendant, and aria-selected synchronized.
• Preserve the current commit model: navigation while the popup is open does not change modelValue until Enter, Space, Tab, or pointer selection commits it.
• Align closed/open behavior with the WAI-ARIA select-only combobox pattern instead of defining a project-specific keyboard contract.

Acceptance criteria

• Home activates the first enabled option and End activates the last enabled option.
• Printable input activates the next matching enabled option using case-insensitive label matching.
• Disabled matches are ignored.
• Keyboard navigation keeps the active option visible in a scrollable listbox.
• Focus remains on the combobox trigger while navigating.
• Focused Playwright coverage exercises Home, End, typeahead, disabled options, and a list longer than seven options.

References

• https://www.w3.org/WAI/ARIA/apg/patterns/combobox/examples/combobox-select-only/
• https://www.w3.org/WAI/ARIA/apg/patterns/listbox/