Fixed model capabilities and how model names are matched (#958)

app/MindWork AI Studio/Settings/ProviderExtensions.Gateway.cs

@@ -32,7 +32,7 @@ public static partial class ProviderExtensions
         var separatorIndex = model.Id.IndexOf('/');
         var vendor = separatorIndex is -1 ? string.Empty : model.Id[..separatorIndex].ToLowerInvariant();
         var bareModel = separatorIndex is -1 ? model : model with { Id = model.Id[(separatorIndex + 1)..] };
-        var bareModelName = bareModel.Id.ToLowerInvariant().AsSpan();
+        var bareModelName = NormalizeModelId(bareModel.Id).AsSpan();
 
         var capabilities = vendor switch
         {
@@ -69,6 +69,10 @@ public static partial class ProviderExtensions
     /// A gateway serves every model through its OpenAI-compatible chat completion API.
     /// The Responses API is not available there, no matter which API the original
     /// provider offers.
+    ///
+    /// The same holds for a provider which resells a model under its plain name instead of
+    /// prefixing it with the vendor, such as GWDG. Those go through the open source rules, which
+    /// call this for the very same reason.
     /// </remarks>
     private static List<Capability> NormalizeForGateway(List<Capability> capabilities)
     {