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.

backend/Hosts/Musify.Api/OpenApi/OpenApiOptionsSetup.cs

@@ -39,13 +39,6 @@ public sealed class OpenApiOptionsSetup(IOptions<AuthenticationConfiguration> op
             return Task.CompletedTask;
         } );
 
-        // Properties annotated with [JsonConverter(typeof(LongAsStringConverter))] (id-shaped
-        // `long` fields — see that converter for why) serialize as a JSON string, but the
-        // schema generator still reflects the declared CLR `long`/`long?` type as a bare
-        // int64 number. Reconcile the declared schema so generated clients (openapi-typescript)
-        // type exactly those properties as `string`, matching what actually goes over the wire —
-        // scoped to the attribute, not the CLR type, so unrelated `long` fields (byte sizes, …)
-        // are left alone.
         options.AddSchemaTransformer((schema, context, _) =>
         {
             if (context.JsonPropertyInfo?.CustomConverter is LongAsStringConverter or NullableLongAsStringConverter)