Remove comments from backend and web-player source

Strip //, /* */ and XML doc comments from all backend .cs files, and
JS/TS/CSS/HTML comments from web-player source (.ts, .svelte, .css),
per the project's no-comments convention.

web-player/src/routes/+layout.server.ts

@@ -23,7 +23,6 @@ async function fetchSidebarPlaylists(
 		});
 		return data?.items ?? [];
 	} catch {
-		// The sidebar shell must render even when the API is unreachable.
 		return [];
 	}
 }