恢复为.NET Framework 4.8配置

恢复项目为传统的.NET Framework 4.8格式：
- 使用ToolsVersion=15.0
- TargetFrameworkVersion=v4.8
- 手动添加System.WindowsForms等引用
- 移除Modern SDK配置

现在可以安装NDP48-DevPack-CHS来获取开发工具
编译后的程序仍然需要在有.NET Framework 4.8运行时的机器上运行

🤖 Generated with [Claude Code](https://caude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

SlideCombine.csproj

@@ -1,14 +1,70 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" />
   <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{12345678-1234-1234-1234-123456789012}</ProjectGuid>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net6.0-windows</TargetFramework>
-    <UseWindowsForms>true</UseWindowsForms>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>enable</Nullable>
-    <AssemblyName>SlideCombine</AssemblyName>
     <RootNamespace>SlideCombine</RootNamespace>
-    <ApplicationIcon>app.ico</ApplicationIcon>
+    <AssemblyName>SlideCombine</AssemblyName>
+    <TargetFrameworkVersion>v4.8</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <Deterministic>true</Deterministic>
+    <UseWindowsForms>true</UseWindowsForms>
   </PropertyGroup>
-
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Deployment" />
+    <Reference Include="System.Drawing" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Windows.Forms" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="BookmarkExtractor.cs" />
+    <Compile Include="ContentFormatter.cs" />
+    <Compile Include="FileMerger.cs" />
+    <Compile Include="Form1.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="Form1.Designer.cs">
+      <DependentUpon>Form1.cs</DependentUpon>
+    </Compile>
+    <Compile Include="MetadataModel.cs" />
+    <Compile Include="Program.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="Form1.resx">
+      <Generator>ResXFileCodeGenerator</Generator>
+      <LastGenOutput>Form1.Designer.cs</LastGenOutput>
+      <SubType>Designer</SubType>
+    </EmbeddedResource>
+    <EmbeddedResource Include="app.ico" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>