feat: 完成第四批任务 (Task 6.2, 10.1-10.3)

Task 6.2 - 报告导出功能:
- ReportExportService: 报告导出服务
- ExportToMarkdown: Markdown 格式导出
- ExportToHtml: HTML 格式导出（可打印为 PDF）
- ExportToPdf: PDF 导出（HTML 包装）

Task 10.1-10.3 - 文档和打包:
- README.md: 项目主文档
- docs/USAGE.md: 使用指南（CLI 命令、API、Web 界面）
- docs/DEVELOPMENT.md: 开发指南（项目结构、构建、测试、部署）
- docs/API.md: API 参考文档（端点、认证、错误码）
- Dockerfile: Web API Docker 镜像
- docker-compose.yml: Docker Compose 配置
- .dockerignore: Docker 忽略文件
- NuGet 打包配置 (CodePlay.Core.csproj)

测试：42 个 (41 通过，1 跳过) ✅

新增文件:
- CodePlay.Core/Services/ReportExportService.cs
- README.md
- docs/USAGE.md
- docs/DEVELOPMENT.md
- docs/API.md
- Dockerfile
- docker-compose.yml
- .dockerignore
Co-authored-by: monkeycode-ai <monkeycode-ai@chaitin.com>

CodePlay.Core/CodePlay.Core.csproj

@@ -1,14 +1,30 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-  <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>enable</Nullable>
-  </PropertyGroup>
-
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <PackageId>CodePlay.Core</PackageId>
+    <Version>1.0.0</Version>
+    <Authors>CodePlay Team</Authors>
+    <Company>CodePlay</Company>
+    <Description>CodePlay - Professional code conversion engine for C# and Java</Description>
+    <Copyright>Copyright (c) 2026 CodePlay</Copyright>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    <PackageProjectUrl>https://github.com/your-org/codeplay</PackageProjectUrl>
+    <RepositoryUrl>https://github.com/your-org/codeplay</RepositoryUrl>
+    <PackageTags>code-conversion csharp java migration refactoring</PackageTags>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" />
-    <PackageReference Include="TreeSitter" Version="0.1.0-alpha.1" />
-  </ItemGroup>
-
-</Project>
+    <PackageReference Include="TreeSitter" Version="1.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Include="..\README.md" Pack="true" PackagePath="\" />
+  </ItemGroup>
+
+</Project>

CodePlay.Core/Services/ReportExportService.cs

@@ -0,0 +1,102 @@
+using System.Text;
+
+namespace CodePlay.Core.Services;
+
+/// <summary>
+/// 报告导出服务
+/// </summary>
+public interface IReportExportService
+{
+    string ExportToMarkdown(Core.Models.ConversionReport report);
+    string ExportToHtml(Core.Models.ConversionReport report);
+    byte[] ExportToPdf(Core.Models.ConversionReport report);
+}
+
+public class ReportExportService : IReportExportService
+{
+    public string ExportToMarkdown(Core.Models.ConversionReport report)
+    {
+        var sb = new StringBuilder();
+        
+        sb.AppendLine("# 代码转换报告");
+        sb.AppendLine();
+        sb.AppendLine($"**报告 ID**: {report.Id}");
+        sb.AppendLine($"**项目 ID**: {report.ProjectId}");
+        sb.AppendLine($"**创建时间**: {report.CreatedAt:yyyy-MM-dd HH:mm:ss}");
+        sb.AppendLine();
+        
+        sb.AppendLine("## 转换概况");
+        sb.AppendLine();
+        sb.AppendLine($"| 指标 | 数值 |");
+        sb.AppendLine("|------|------|");
+        sb.AppendLine($"| 源语言 | {report.SourceLanguage} |");
+        sb.AppendLine($"| 目标语言 | {report.TargetLanguage} |");
+        sb.AppendLine($"| 转换行数 | {report.LinesConverted} |");
+        sb.AppendLine($"| 转换类数 | {report.ClassesConverted} |");
+        sb.AppendLine($"| 转换方法数 | {report.MethodsConverted} |");
+        sb.AppendLine($"| 问题数 | {report.IssueCount} |");
+        sb.AppendLine($"| TODO 数 | {report.TodoCount} |");
+        sb.AppendLine($"| 验证状态 | {report.ValidationStatus} |");
+        sb.AppendLine();
+        
+        if (report.TodoItems.Any())
+        {
+            sb.AppendLine("## 不可转换语法 (TODO)");
+            sb.AppendLine();
+            foreach (var todo in report.TodoItems)
+            {
+                sb.AppendLine($"### {todo.Description}");
+                sb.AppendLine($"- **原因**: {todo.WhyNotDirect}");
+                sb.AppendLine($"- **建议**: {todo.RecommendedAlternative}");
+                sb.AppendLine();
+            }
+        }
+        
+        if (report.Issues.Any())
+        {
+            sb.AppendLine("## 问题列表");
+            sb.AppendLine();
+            foreach (var issue in report.Issues)
+            {
+                sb.AppendLine($"### {issue.Description}");
+                sb.AppendLine($"- **严重程度**: {issue.Severity}");
+                sb.AppendLine($"- **建议**: {issue.Suggestion}");
+                sb.AppendLine();
+            }
+        }
+        
+        sb.AppendLine("## 转换日志");
+        sb.AppendLine();
+        foreach (var log in report.TransformationLog)
+        {
+            sb.AppendLine($"- [{log.Timestamp:HH:mm:ss}] {log.Operation}: {log.Details}");
+        }
+        
+        return sb.ToString();
+    }
+    
+    public string ExportToHtml(Core.Models.ConversionReport report)
+    {
+        var markdown = ExportToMarkdown(report);
+        var title = "代码转换报告 - " + report.Id;
+        
+        var html = markdown
+            .Replace("# ", "<h1>")
+            .Replace("## ", "</h1><h2>")
+            .Replace("### ", "</h2><h3>")
+            .Replace("**", "<strong>")
+            .Replace("\n", "<br/>");
+        
+        var htmlFull = "<!DOCTYPE html><html><head><meta charset='utf-8'><title>" + title + "</title><style>body { font-family: Arial, sans-serif; max-width: 900px; margin: 0 auto; padding: 20px; } h1 { color: #333; border-bottom: 2px solid #007bff; padding-bottom: 10px; } h2 { color: #555; margin-top: 30px; } table { border-collapse: collapse; width: 100%; margin: 20px 0; } th, td { border: 1px solid #ddd; padding: 8px; text-align: left; } th { background-color: #007bff; color: white; }</style></head><body>" + html + "</body></html>";
+        
+        return htmlFull;
+    }
+    
+    public byte[] ExportToPdf(Core.Models.ConversionReport report)
+    {
+        // MVP 版本：生成 HTML，用户可以使用浏览器打印为 PDF
+        // 完整实现需要引入 iText7 或 PuppeteerSharp
+        var html = ExportToHtml(report);
+        return Encoding.UTF8.GetBytes(html);
+    }
+}