优化渲染逻辑和界面布局

在 `MarkdownWpfRenderer.cs` 中，更新了 `RenderHtmlBlock` 方法以处理以 `<think>` 开头的文本，返回包含进度条和可选择文本块的 `Expander` 控件。更新了 `App.xaml`，移除了 `mu:ThemeDictionary` 的 `ColorMode` 属性。修改了 `AiMessageControll.xaml`，将布局从 `StackPanel` 更改为 `DockPanel`，并添加了 `ButtonGroup`。在 `ImportViewModel.cs` 中，调整了调试模式下的消息处理逻辑，确保正确处理用户输入的消息。

src/EleCho.MdViewer/src/EleCho.MdViewer/Markdown/MarkdownWpfRenderer.cs

@@ -379,7 +379,6 @@ public class MarkdownWpfRenderer
         if (text.StartsWith("<think>"))
         {
             text = text.Replace("<think>", "").Replace("</think>", "");
-        }
             var htmlText = new SelectableTextBlock();
             htmlText.Text = text;
             var expander = new Expander();
@@ -388,6 +387,14 @@ public class MarkdownWpfRenderer
             expander.Header = header;
             expander.Content = htmlText;
             return expander;
+        }
+        else
+        {
+            var htmlText = new SelectableTextBlock();
+            htmlText.Text = text;
+            return htmlText;
+        }
+        
 
     }
     public FrameworkElement RenderMathBlock(MathBlock mathBlock, CancellationToken cancellationToken)

src/ExcelHelper/AI/PromptUtil.cs

@@ -50,17 +50,6 @@ class PromptUtil
 5. 尽量使用比较简短与易懂的公式来回答用户的问题，避免用户无法理解。
 
 
-
-首先，在<思考>标签中详细说明你解答此问题的思考过程。然后，在<回答>标签中给出最终的回答。
-
-<think>
-
-[在此详细说明你的思考过程]
-
-</think>
-
-[在此给出你的回答]
-
 ";
     }
 }

src/ExcelHelper/App.xaml

@@ -12,7 +12,7 @@
                 <ResourceDictionary Source="pack://application:,,,/HandyControl;component/Themes/SkinDefault.xaml" />
                 <ResourceDictionary Source="pack://application:,,,/HandyControl;component/Themes/Theme.xaml" />
                 <mu:ControlsDictionary />
-                <mu:ThemeDictionary ColorMode="Light" />
+                <mu:ThemeDictionary />
             </ResourceDictionary.MergedDictionaries>
 
         </ResourceDictionary>

src/ExcelHelper/Views/Components/AiMessageControll.xaml

@@ -88,6 +88,15 @@
                                     </TabItem>
                                 </TabControl>
 
+                                <DockPanel>
+                                    <hc:ButtonGroup Margin="5,0">
+                                        <Button
+                                            Height="20"
+                                            hc:IconElement.Geometry="{StaticResource WindowRestoreGeometry}"
+                                            Background="Transparent"
+                                            FontSize="10"
+                                            Foreground="#99000000" />
+                                    </hc:ButtonGroup>
                                     <StackPanel HorizontalAlignment="Right" Orientation="Horizontal">
                                         <TextBlock
                                             Margin="0,5,5,0"
@@ -100,6 +109,7 @@
                                             Foreground="#99000000"
                                             Text="{Binding Timestamp, StringFormat='{}{0:HH:mm}'}" />
                                     </StackPanel>
+                                </DockPanel>
                                 <hc:Divider
                                     Height="10"
                                     Margin="0,3"

src/ExcelHelper/Views/ViewModels/ImportViewModel.cs

@@ -321,8 +321,9 @@ public partial class ImportViewModel : ObservableRecipient, IViewModel
             };
            
             Messages.Add(aiChat);
-#if !DEBUG
-            var results = TEST_AI_CONTENT.Split('\n');
+            var promptedMsg = PromptUtil.UsePrompt(message,ExcelPromptString);
+#if DEBUG
+            var results = promptedMsg.Split('\n');
             foreach(var result in results)
             {
                 aiChat.Content += result;
@@ -330,7 +331,6 @@ public partial class ImportViewModel : ObservableRecipient, IViewModel
                 await Task.Delay(5);
             }
 #else
-            var promptedMsg = PromptUtil.UsePrompt(message,ExcelPromptString);
             history.Add(new Microsoft.Extensions.AI.ChatMessage
             {
                 Role = Microsoft.Extensions.AI.ChatRole.User,