refactor: 优化组件导出并移除未使用的组件并清理冗余代码

src/components/ui/badge.tsx

@@ -22,11 +22,11 @@ const badgeVariants = cva(
   },
 );
 
-export interface BadgeProps
+interface BadgeProps
   extends React.HTMLAttributes<HTMLDivElement>, VariantProps<typeof badgeVariants> {}
 
 function Badge({ className, variant, ...props }: BadgeProps) {
   return <div className={cn(badgeVariants({ variant }), className)} {...props} />;
 }
 
-export { Badge, badgeVariants };
+export { Badge };

src/components/ui/button.tsx

@@ -46,4 +46,4 @@ const Button = React.forwardRef<HTMLButtonElement, ButtonProps>(
 );
 Button.displayName = 'Button';
 
-export { Button, buttonVariants };
+export { Button };

src/components/ui/select.tsx

@@ -124,27 +124,4 @@ const SelectItem = React.forwardRef<
 ));
 SelectItem.displayName = SelectPrimitive.Item.displayName;
 
-const SelectSeparator = React.forwardRef<
-  React.ComponentRef<typeof SelectPrimitive.Separator>,
-  React.ComponentPropsWithoutRef<typeof SelectPrimitive.Separator>
->(({ className, ...props }, ref) => (
-  <SelectPrimitive.Separator
-    ref={ref}
-    className={cn('-mx-1 my-1 h-px bg-muted', className)}
-    {...props}
-  />
-));
-SelectSeparator.displayName = SelectPrimitive.Separator.displayName;
-
-export {
-  Select,
-  SelectGroup,
-  SelectValue,
-  SelectTrigger,
-  SelectContent,
-  SelectLabel,
-  SelectItem,
-  SelectSeparator,
-  SelectScrollUpButton,
-  SelectScrollDownButton,
-};
+export { Select, SelectGroup, SelectValue, SelectTrigger, SelectContent, SelectLabel, SelectItem };