Implemented the transcription API (#623)

app/MindWork AI Studio/Provider/Perplexity/ProviderPerplexity.cs

@@ -34,7 +34,7 @@ public sealed class ProviderPerplexity() : BaseProvider(LLMProviders.PERPLEXITY,
     public override async IAsyncEnumerable<ContentStreamChunk> StreamChatCompletion(Model chatModel, ChatThread chatThread, SettingsManager settingsManager, [EnumeratorCancellation] CancellationToken token = default)
     {
         // Get the API key:
-        var requestedSecret = await RUST_SERVICE.GetAPIKey(this);
+        var requestedSecret = await RUST_SERVICE.GetAPIKey(this, SecretStoreType.LLM_PROVIDER);
         if(!requestedSecret.Success)
             yield break;
         
@@ -88,6 +88,12 @@ public sealed class ProviderPerplexity() : BaseProvider(LLMProviders.PERPLEXITY,
         yield break;
     }
     #pragma warning restore CS1998 // Async method lacks 'await' operators and will run synchronously
+    
+    /// <inheritdoc />
+    public override Task<string> TranscribeAudioAsync(Model transcriptionModel, string audioFilePath, SettingsManager settingsManager, CancellationToken token = default)
+    {
+        return Task.FromResult(string.Empty);
+    }
 
     /// <inheritdoc />
     public override Task<IEnumerable<Model>> GetTextModels(string? apiKeyProvisional = null, CancellationToken token = default)