applied various optimisations to UI

src/interface/components/BackgroundSelector.tsx

@@ -2,7 +2,6 @@ import { ChangeEvent, memo, useEffect, useState } from "react";
 import { downloadPresetBackground, openDB, readAllData, writeData } from "../hooks/BackgroundDataLoader";
 import presetBackgrounds from "../assets/presetBackgrounds";
 import "./BackgroundSelector.css";
-import browser from "webextension-polyfill";
 
 export interface Background {
   id: string;

src/interface/components/ThemeCover.tsx

@@ -14,7 +14,7 @@ type ThemeCoverProps = {
   onThemeDelete: (themeId: string) => void;
 };
 
-export const ThemeCover: React.FC<ThemeCoverProps> = ({
+export const ThemeCover: React.FC<ThemeCoverProps> = React.memo(({
   theme,
   downloaded,
   isSelected,
@@ -96,7 +96,7 @@ export const ThemeCover: React.FC<ThemeCoverProps> = ({
       </div>
     </button>
   );
-};
+});
 
 const LoadingSpinner = ({ size }: { size: number }) => {
   return <div style={{ width: `${size}px`, height: `${size}px` }} className={`animate-spin rounded-full border-2 border-white border-t-2 border-t-transparent`}></div>;