Spec for porting AddEventDialog UX patterns into TaskFormDialog: new
header (title + description, no separator), full keyboard navigation
(roving focus on pills, arrow nav, Enter to open popover, arrow nav
inside list popovers and calendar), and date+time keyboard entry via
extended DateField (withTime + flat props) and parseDate time suffix.
Includes interactive HTML mockup demonstrating the keyboard flow.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>