feat: Complete cross-platform build system and folder reorganization

- Reorganize project structure: Port/ → DotNet/, VC/, C++/
- Add comprehensive cross-platform build automation
  - Windows: build_all.bat, build.bat files for all components
  - Linux/macOS: build_all.sh, build.sh files for all components
- Update all build scripts with correct folder paths
- Create test automation scripts (test_all.bat/sh)
- Update documentation to reflect new structure
- Maintain 100% roundtrip accuracy for test5.exi (pure EXI)
- Support both Windows MSBuild and Linux GCC compilation

🤖 Generated with [Claude Code](https://claude.ai/code)

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

DotNet/build.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+echo "Building .NET V2GDecoder Project..."
+
+# .NET Core 빌드
+echo "Building Debug configuration..."
+dotnet build V2GDecoderNet.csproj -c Debug
+if [ $? -ne 0 ]; then
+    echo "ERROR: Debug 빌드 실패"
+    exit 1
+fi
+
+echo "Building Release configuration..."
+dotnet build V2GDecoderNet.csproj -c Release
+if [ $? -ne 0 ]; then
+    echo "ERROR: Release 빌드 실패"
+    exit 1
+fi
+
+echo
+echo "✅ .NET 빌드가 성공적으로 완료되었습니다"
+echo
+echo "생성된 파일들:"
+[ -f "bin/Debug/net8.0/V2GDecoderNet.dll" ] && echo "  📦 Debug: bin/Debug/net8.0/V2GDecoderNet.dll"
+[ -f "bin/Release/net8.0/V2GDecoderNet.dll" ] && echo "  📦 Release: bin/Release/net8.0/V2GDecoderNet.dll"
+
+echo
+echo "사용법:"
+echo "  dotnet run V2GDecoderNet.csproj ../Sample/test5.exi"
+echo "  dotnet bin/Release/net8.0/V2GDecoderNet.dll ../Sample/test5.exi"