Range Presets

The component is self-contained: one file, zero dependencies, its own palette in local variables --vibeui-calendar-027-*. Client-side: the selected preset and both bounds live in useState. The presets are expanded by the pure function resolve from the today reference date, which arrives as a prop — Date.now() inside the component would split the server and the client render. The date fields are native input type="date" with mutual min and max, so the browser itself does not let the period be reversed; editing by hand moves the choice into the custom state. The total counts the number of days inclusive and declines it through pluralize, while an invalid period (the end earlier than the start) is shown as separate text on a muted backing. The theme comes from the surrounding color-scheme through light-dark(): the component has no surface of its own by default, it sits directly on the page background and darkens along with it, while the background prop brings the panel back. The preset, field and total captions arrive in props, the Russian values sit in the defaults.