Use osu-default-background as fallback in mediaSession

Two very scuffed things I had to do in order to achieve this: First, for some god forsaken reason I can't import any images in the backend routers without adding a types file and explicitly saying I can add images. Second, I have no idea why, but sharp (library I'm using for resizing images) just WILL NOT let me use a buffer converted from base64 from the default image, so I had to manually resize the default image to 512x512, add it to the project, and import it.

src/main/router/index.d.ts

@@ -0,0 +1 @@
+declare module "*.jpg";

src/main/router/resource-router.ts

@@ -2,6 +2,7 @@ import { Router } from "../lib/route-pass/Router";
 import { Storage } from "../lib/storage/Storage";
 import { none, some } from "../lib/rust-like-utils-backend/Optional";
 import { fail, ok } from "../lib/rust-like-utils-backend/Result";
+import defaultBackground from "../../renderer/src/assets/osu-default-background-small.jpg";
 import path from "path";
 import sharp from "sharp";
 
@@ -21,17 +22,16 @@ Router.respond("resource::getPath", (_evt, id) => {
 });
 
 Router.respond("resource::getMediaSessionImage", async (_evt, bgPath) => {
+  if (bgPath === undefined) {
+    return some(defaultBackground);
+  }
   const settings = Storage.getTable("settings");
   const songsDir = settings.get("osuSongsDir");
   if (songsDir.isNone) {
     return none();
   }
 
   const pathToBg = path.join(songsDir.value, bgPath);
-  if (pathToBg === undefined) {
-    // handle no bg
-    return none();
-  }
   const mimeType = `image/${path.extname(pathToBg).slice(1)}`;
   const buffer = await sharp(pathToBg).resize(512, 512).toBuffer();