AX Agent 폴더 데이터 활용 사용자 옵션 제거 및 자동 정책 고정

- 코워크/코드의 폴더 내 문서 활용을 사용자 설정에서 제거하고 탭별 자동 정책으로 고정
- ChatWindow 하단 데이터 활용 버튼과 AX Agent 내부 설정 row, 메인 설정/구형 설정창의 관련 UI 제거
- Chat/Cowork/Code 탭별 자동 데이터 활용 정책을 none/passive/active로 고정하고 저장 경로에서 사용자 선택값 반영 제거
- README와 DEVELOPMENT 문서에 변경 이력 및 적용 기준 반영
- 검증: dotnet build src/AxCopilot/AxCopilot.csproj -c Release -v minimal -p:OutputPath=bin\verify\ -p:IntermediateOutputPath=obj\verify\ (경고 0 / 오류 0)

src/AxCopilot/Views/AgentSettingsWindow.xaml.cs

@@ -17,7 +17,6 @@ public partial class AgentSettingsWindow : Window
     private readonly LlmSettings _llm;
     private string _permissionMode = PermissionModeCatalog.Deny;
     private string _reasoningMode = "detailed";
-    private string _folderDataUsage = "active";
     private string _operationMode = OperationModePolicy.InternalMode;
     private string _displayMode = "rich";
     private string _defaultOutputFormat = "auto";
@@ -48,7 +47,6 @@ public partial class AgentSettingsWindow : Window
         ModelInput.Text = _selectedModel;
         _permissionMode = PermissionModeCatalog.NormalizeGlobalMode(_llm.FilePermission);
         _reasoningMode = string.IsNullOrWhiteSpace(_llm.AgentDecisionLevel) ? "detailed" : _llm.AgentDecisionLevel;
-        _folderDataUsage = string.IsNullOrWhiteSpace(_llm.FolderDataUsage) ? "active" : _llm.FolderDataUsage;
         _operationMode = OperationModePolicy.Normalize(_settings.Settings.OperationMode);
         _displayMode = "rich";
         _defaultOutputFormat = string.IsNullOrWhiteSpace(_llm.DefaultOutputFormat) ? "auto" : _llm.DefaultOutputFormat;
@@ -114,7 +112,6 @@ public partial class AgentSettingsWindow : Window
         BtnOperationMode.Content = BuildOperationModeLabel(_operationMode);
         BtnPermissionMode.Content = PermissionModeCatalog.ToDisplayLabel(_permissionMode);
         BtnReasoningMode.Content = BuildReasoningModeLabel(_reasoningMode);
-        BtnFolderDataUsage.Content = BuildFolderDataUsageLabel(_folderDataUsage);
     }
 
     private void RefreshDisplayModeCards()
@@ -173,16 +170,6 @@ public partial class AgentSettingsWindow : Window
         };
     }
 
-    private static string BuildFolderDataUsageLabel(string mode)
-    {
-        return (mode ?? "none").ToLowerInvariant() switch
-        {
-            "active" => "적극 활용",
-            "passive" => "소극 활용",
-            _ => "활용하지 않음",
-        };
-    }
-
     private static string BuildOutputFormatLabel(string format)
     {
         return (format ?? "auto").ToLowerInvariant() switch
@@ -469,17 +456,6 @@ public partial class AgentSettingsWindow : Window
         RefreshModeLabels();
     }
 
-    private void BtnFolderDataUsage_Click(object sender, RoutedEventArgs e)
-    {
-        _folderDataUsage = _folderDataUsage switch
-        {
-            "none" => "passive",
-            "passive" => "active",
-            _ => "none",
-        };
-        RefreshModeLabels();
-    }
-
     private void BtnDefaultOutputFormat_Click(object sender, RoutedEventArgs e)
     {
         _defaultOutputFormat = (_defaultOutputFormat ?? "auto").ToLowerInvariant() switch
@@ -514,7 +490,6 @@ public partial class AgentSettingsWindow : Window
         _llm.FilePermission = _permissionMode;
         _llm.DefaultAgentPermission = _permissionMode;
         _llm.AgentDecisionLevel = _reasoningMode;
-        _llm.FolderDataUsage = _folderDataUsage;
         _llm.AgentUiExpressionLevel = "rich";
         _llm.DefaultOutputFormat = _defaultOutputFormat;
         _llm.DefaultMood = _defaultMood;