fix: widen split grid settings modal for 7 layout options

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/SplitGridSettingsModal.tsx

@@ -178,7 +178,7 @@ export function SplitGridSettingsModal({
   return (
     <div className="fixed inset-0 z-[100] flex items-center justify-center bg-black/50">
       <div
-        className="bg-neutral-800 rounded-lg p-6 w-[520px] border border-neutral-700 shadow-xl"
+        className="bg-neutral-800 rounded-lg p-6 w-[600px] border border-neutral-700 shadow-xl"
         onKeyDown={handleKeyDown}
       >
         <h2 className="text-lg font-semibold text-neutral-100 mb-4">