Restructured the project structure back to the way it was, there's no reasonable way to split the modules

src/NadekoBot/_common/Attributes/OnlyPublicBotAttribute.cs

@@ -0,0 +1,21 @@
+#nullable disable
+using System.Diagnostics.CodeAnalysis;
+
+namespace NadekoBot.Common;
+
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)]
+[SuppressMessage("Style", "IDE0022:Use expression body for methods")]
+public sealed class OnlyPublicBotAttribute : PreconditionAttribute
+{
+    public override Task<PreconditionResult> CheckPermissionsAsync(
+        ICommandContext context,
+        CommandInfo command,
+        IServiceProvider services)
+    {
+#if GLOBAL_NADEKO || DEBUG
+        return Task.FromResult(PreconditionResult.FromSuccess());
+#else
+        return Task.FromResult(PreconditionResult.FromError("Only available on the public bot."));
+#endif
+    }
+}