fix: throw if provider is null

src/dumper/dumper.cs

@@ -263,6 +263,8 @@ class Dumper
 
     private void ExportIcon(string assetPath, string outPath)
     {
+        if (_provider == null) throw new InvalidOperationException("Attempted to export icon when dumper was not initialized/invalid");
+
         string cleanPath = assetPath.Contains('.') ? assetPath[..assetPath.LastIndexOf('.')] : assetPath;
         string fileName = Path.GetFileName(cleanPath) + ".png";
         string relativeOutPath = outPath.TrimStart('/', '\\');
@@ -273,7 +275,6 @@ class Dumper
 
         if (File.Exists(fullPath)) return;
 
-        if (_provider == null) return;
         // special thanks to whichever dev kept fucking up the casing
         if (!_provider.TryLoadPackage(cleanPath, out IPackage? package))
         {