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/Core/Musify.Application/Configuration/GetPlaybackPublicConfig.cs

@@ -3,8 +3,7 @@ using Musify.Application.Configuration.Responses;
 
 namespace Musify.Application.Configuration
 {
-    /// <summary>Reads the parts of <see cref="PlaybackConfiguration"/> that are safe to expose to an
-    /// unauthenticated client, so it can decide whether to gate the app behind sign-in at all.</summary>
+
     public record GetPlaybackPublicConfigQuery : IQuery<PlaybackPublicConfigResponse>;
 
     public class GetPlaybackPublicConfigQueryHandler(PlaybackConfiguration playbackConfiguration)