fix(ui): widen pagination page-size selector to fit 3-digit values

Previous 70px width clipped '200' option (added in 51cf1037). Bumped
to 84px to accommodate 3-digit page sizes plus the dropdown chevron.

ui/web/src/components/shared/pagination.tsx

@@ -47,7 +47,7 @@ export function Pagination({
             value={String(pageSize)}
             onValueChange={(v) => onPageSizeChange(Number(v))}
           >
-            <SelectTrigger size="sm" className="w-[70px]">
+            <SelectTrigger size="sm" className="w-[84px]">
               <SelectValue />
             </SelectTrigger>
             <SelectContent>