Fix: auto-save grid size changes and dynamically scale grid item heights based on grid size

frontend/src/components/FileExplorer.tsx

@@ -2098,7 +2098,7 @@ export default function FileExplorer({ onLogout }: FileExplorerProps) {
                         <Pin className="absolute top-2 right-2 w-3 h-3" style={{ color: 'var(--color-warning)' }} />
                       )}
                       <div className="flex flex-col items-center gap-3">
-                        <div className="w-full h-32 flex items-center justify-center">
+                        <div className="w-full flex items-center justify-center" style={{ height: `calc(${gridSize}px * 0.65)` }}>
                           {getFileIcon(file, true)}
                         </div>
                         {renaming === file.path ? (

frontend/src/components/SettingsPage.tsx

@@ -136,6 +136,8 @@ export default function SettingsPage({ onLogout }: SettingsPageProps) {
               step="10"
               value={settings.grid_size}
               onChange={(e) => setSettings({ ...settings, grid_size: e.target.value })}
+              onMouseUp={handleSave}
+              onTouchEnd={handleSave}
               className="w-full max-w-xs accent-[var(--color-accent)]"
             />
           </div>