feat: add Calendar component and update DatePicker with latest shadcn/ui improvements

- Add standalone Calendar component following latest shadcn/ui patterns
- Update DatePicker day_outside styling for better contrast (Nov 3, 2024 update)
- Remove opacity-50 and aria-selected:opacity-30 from day_outside for improved accessibility
- Export Calendar component in UI index
- Maintain backward compatibility with existing DatePicker usage

Author: codegen-sh[bot]

packages/components/src/ui/calendar.tsx

@@ -0,0 +1,56 @@
+import { ChevronLeft, ChevronRight } from 'lucide-react';
+import type * as React from 'react';
+import { type CustomComponents, DayPicker } from 'react-day-picker';
+import { buttonVariants } from './button';
+import { cn } from './utils';
+
+export type CalendarProps = React.ComponentProps<typeof DayPicker>;
+
+function Calendar({ className, classNames, showOutsideDays = true, ...props }: CalendarProps) {
+  return (
+    <DayPicker
+      showOutsideDays={showOutsideDays}
+      className={cn('p-3', className)}
+      data-slot="calendar"
+      classNames={{
+        months: 'flex flex-col sm:flex-row space-y-4 sm:space-x-4 sm:space-y-0',
+        month: 'space-y-4',
+        caption: 'flex justify-center pt-1 relative items-center',
+        caption_label: 'text-sm font-medium',
+        nav: 'space-x-1 flex items-center',
+        nav_button: cn(
+          buttonVariants({ variant: 'outline' }),
+          'h-7 w-7 bg-transparent p-0 opacity-50 hover:opacity-100',
+        ),
+        nav_button_previous: 'absolute left-1',
+        nav_button_next: 'absolute right-1',
+        table: 'w-full border-collapse space-y-1',
+        head_row: 'flex',
+        head_cell: 'text-muted-foreground rounded-md w-9 font-normal text-[0.8rem]',
+        row: 'flex w-full mt-2',
+        cell: 'h-9 w-9 text-center text-sm p-0 relative [&:has([aria-selected].day-range-end)]:rounded-r-md [&:has([aria-selected].day-outside)]:bg-accent/50 [&:has([aria-selected])]:bg-accent first:[&:has([aria-selected])]:rounded-l-md last:[&:has([aria-selected])]:rounded-r-md focus-within:relative focus-within:z-20',
+        day: cn(buttonVariants({ variant: 'ghost' }), 'h-9 w-9 p-0 font-normal aria-selected:opacity-100'),
+        day_range_end: 'day-range-end',
+        day_selected:
+          'bg-primary text-primary-foreground hover:bg-primary hover:text-primary-foreground focus:bg-primary focus:text-primary-foreground',
+        day_today: 'bg-accent text-accent-foreground',
+        day_outside:
+          'day-outside text-muted-foreground aria-selected:bg-accent/50 aria-selected:text-muted-foreground',
+        day_disabled: 'text-muted-foreground opacity-50',
+        day_range_middle: 'aria-selected:bg-accent aria-selected:text-accent-foreground',
+        day_hidden: 'invisible',
+        ...classNames,
+      }}
+      components={
+        {
+          IconLeft: ({ ...props }) => <ChevronLeft className="h-4 w-4" {...props} />,
+          IconRight: ({ ...props }) => <ChevronRight className="h-4 w-4" {...props} />,
+        } as Partial<CustomComponents>
+      }
+      {...props}
+    />
+  );
+}
+
+export { Calendar };
+

packages/components/src/ui/date-picker.tsx

@@ -35,7 +35,7 @@ function DatePicker({ className, classNames, showOutsideDays = true, ...props }:
           'bg-primary text-primary-foreground hover:bg-primary hover:text-primary-foreground focus:bg-primary focus:text-primary-foreground',
         day_today: 'bg-accent text-accent-foreground',
         day_outside:
-          'day-outside text-muted-foreground opacity-50 aria-selected:bg-accent/50 aria-selected:text-muted-foreground aria-selected:opacity-30',
+          'day-outside text-muted-foreground aria-selected:bg-accent/50 aria-selected:text-muted-foreground',
         day_disabled: 'text-muted-foreground opacity-50',
         day_range_middle: 'aria-selected:bg-accent aria-selected:text-accent-foreground',
         day_hidden: 'invisible',

packages/components/src/ui/index.ts

@@ -1,4 +1,5 @@
 export * from './button';
+export * from './calendar';
 export * from './checkbox-field';
 export * from './date-picker';
 export * from './date-picker-field';