Added transcription for Helmholtz and Groq, embeddings for GWDG, and fixed Mistral model capabilities (#942)

app/MindWork AI Studio/Tools/Services/MediaTranscriptionService.cs

@@ -531,7 +531,15 @@ public sealed class MediaTranscriptionService(
                     fileName,
                     operation.Id,
                     providerResult.ErrorMessage);
-                return MediaTranscriptionResult.Failed(TB("The transcription provider could not transcribe the media file."));
+
+                //
+                // When the provider told us why it failed, the user gets to read it. Only that
+                // message says whether to wait, to check the API key, or to ask the provider for
+                // a format it can read:
+                //
+                return MediaTranscriptionResult.Failed(string.IsNullOrWhiteSpace(providerResult.ErrorMessage)
+                    ? TB("The transcription provider could not transcribe the media file.")
+                    : providerResult.ErrorMessage);
             }
 
             return MediaTranscriptionResult.Succeeded(providerResult.Text.Trim());