Improve loadImage to use a placeholder and prevent game crash

engine/lib/loadImage.ts

@@ -1,3 +1,8 @@
+import missingTextureSrc from "./missingTexture.svg?url";
+
+const placeholder = new Image();
+placeholder.src = missingTextureSrc;
+
 export function loadImage(src: string): Promise<HTMLImageElement> {
 	return new Promise((resolve) => {
 		const image = new Image();
@@ -5,7 +10,7 @@ export function loadImage(src: string): Promise<HTMLImageElement> {
 		image.onload = () => resolve(image);
 		image.onerror = (error) => {
 			console.error(error);
-			resolve(image);
+			resolve(placeholder);
 		};
 
 		image.src = src;