fix file content extractor mechanism ...

Providers/XAIServiceBase.cs

@@ -27,6 +27,7 @@ using Microsoft.Extensions.AI;
 using Microsoft.AspNetCore.Http;
 using System.Collections.Generic;
 using Microsoft.Extensions.Logging;
+using xAiApi.Interfaces.Extractors;
 using System.ClientModel.Primitives;
 using System.Runtime.CompilerServices;
 
@@ -52,6 +53,7 @@ namespace xAiApi.Providers
         private readonly ILogger<XAIServiceBase> logger;
         private readonly XAiApiConfiguration configuration;
         private readonly XValidationProvider validationProvider;
+        private readonly IXFileContentExtractor fileContentExtractor;
 
         protected XAIServiceBase(
             IXFileProvider fileProvider,
@@ -59,6 +61,7 @@ namespace xAiApi.Providers
             ILogger<XAIServiceBase> logger,
             XAiApiConfiguration configuration,
             XValidationProvider validationProvider,
+            IXFileContentExtractor fileContentExtractor,
             string model = null
         )
         {
@@ -68,6 +71,7 @@ namespace xAiApi.Providers
             this.dataProvider = dataProvider;
             this.configuration = configuration;
             this.validationProvider = validationProvider;
+            this.fileContentExtractor = fileContentExtractor;
 
             //
             // Prepare Embedding Model Descriptor ...