fix: extend file drop zone to fill remaining viewport height

app/[locale]/files/page.tsx

@@ -395,7 +395,7 @@ export default function FilesPage() {
               </div>
             )}
 
-            <div className="flex-1 min-h-0">
+            <div className="flex-1 min-h-0 flex flex-col">
               {!filesEnabled ? (
                 <div className="flex items-center justify-center h-full">
                   <div className="max-w-lg text-center space-y-3 px-4">

components/files/file-browser.tsx

@@ -837,7 +837,7 @@ export function FileBrowser({
   return (
     <div
       ref={containerRef}
-      className="flex flex-col h-full"
+      className="flex flex-col flex-1 min-h-0"
       onClick={handleContainerClick}
       onDragOver={handleDragOver}
       onDragLeave={handleDragLeave}