Fix GuLuLu image 404 when install folder casing differs

The GuLuLu gif path was hardcoded as /extensions/kaytool/, but ComfyUI
serves the web directory under the custom_nodes folder name and aiohttp
route matching is case-sensitive. Installs that end up with a KayTool
folder (e.g. via ComfyUI-Manager, whose node list points at the
capitalized repo URL) got a 404 for the gif.

Derive the path from import.meta.url so it resolves correctly whatever
the folder is named.

web/gululu.js

@@ -13,7 +13,7 @@ const KayGuLuLuManager = {
     pixelCanvas: null,
     pixelCtx: null,
     pixelDataCache: null,
-    imgSrc: "/extensions/kaytool/resources/GuLuLu.gif",
+    imgSrc: new URL("./resources/GuLuLu.gif", import.meta.url).pathname,
     effectiveBounds: null,
     isAnimating: false,
     animationTimer: null,