refactor(control): improve code quality

control/frontend/src/lib/ts/file_transfer_handler.ts

@@ -59,7 +59,7 @@ export async function add_upload(
 		};
 		const file_primary_key = get_file_primary_key(db_file);
 
-		if (Object.prototype.hasOwnProperty.call(file_transfer_tasks, file_primary_key))
+		if (Object.hasOwn(file_transfer_tasks, file_primary_key))
 			return show_already_in_tasks_error(db_file, 'upload'); // file is already in task
 
 		await db.files.put(db_file);

control/frontend/src/routes/FileView.svelte

@@ -59,9 +59,10 @@
 	$effect(() => {
 		const s = $selected_file_ids;
 		one_file_selected = liveQuery(async () => {
+			if (s.length !== 1) return false
 			const inode = await get_file_by_id(s[0]);
 			if (!inode) return false;
-			return s.length === 1 && !is_folder(inode);
+			return !is_folder(inode);
 		});
 	});