[frontend] fix shell z-index

Author: velzie

frontend/src/components/Shell.tsx

@@ -101,7 +101,7 @@ Shell.style = css`
 		transform-style: flat;
 	}
 	.container.active {
-		z-index: 1;
+		z-index: 0;
 	}
 	.container .devtools {
 		position: relative;