feat: implement tweakable utility workers concurrency, instead of hard-coded value set to 5

spotizerr-ui/src/contexts/SettingsProvider.tsx

@@ -32,6 +32,7 @@ export type FlatAppSettings = {
 	deezer: string;
 	deezerQuality: "MP3_128" | "MP3_320" | "FLAC";
 	maxConcurrentDownloads: number;
+	utilityConcurrency: number;
 	realTime: boolean;
 	fallback: boolean;
 	convertTo: "MP3" | "AAC" | "OGG" | "OPUS" | "FLAC" | "WAV" | "ALAC" | "";
@@ -72,6 +73,7 @@ const defaultSettings: FlatAppSettings = {
 	deezer: "",
 	deezerQuality: "MP3_128",
 	maxConcurrentDownloads: 3,
+	utilityConcurrency: 1,
 	realTime: false,
 	fallback: false,
 	convertTo: "",
@@ -135,6 +137,7 @@ const fetchSettings = async (): Promise<FlatAppSettings> => {
 			// Ensure required frontend-only fields exist
 			recursiveQuality: Boolean((camelData as any).recursiveQuality ?? false),
 			realTimeMultiplier: Number((camelData as any).realTimeMultiplier ?? 0),
+			utilityConcurrency: Number((camelData as any).utilityConcurrency ?? 1),
 			// Ensure watch subkeys default if missing
 			watch: {
 				...(camelData.watch as any),