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>

VC/build.sh

@@ -0,0 +1,41 @@
+#!/bin/bash
+echo "Building V2GDecoder with GCC (Linux alternative to VC++ MSBuild)..."
+
+# GCC로 VC 소스 컴파일
+gcc -I"src" \
+    -I"src/codec" \
+    -I"src/iso1" \
+    -I"src/iso2" \
+    -I"src/din" \
+    -I"src/xmldsig" \
+    -I"src/appHandshake" \
+    -I"src/transport" \
+    -I"src/compat" \
+    -Wall -O2 \
+    V2GDecoder.c \
+    src/codec/*.c \
+    src/iso1/*.c \
+    src/iso2/*.c \
+    src/din/*.c \
+    src/xmldsig/*.c \
+    src/appHandshake/*.c \
+    src/transport/*.c \
+    -o V2GDecoder
+
+if [ $? -eq 0 ]; then
+    echo "✅ Build successful! V2GDecoder created."
+    echo
+    echo "Usage:"
+    echo "  ./V2GDecoder ../Sample/test5.exi"
+    echo
+    echo "Note: This is GCC build alternative to Windows MSBuild."
+    echo "      For Windows VC++ build, use build.bat instead."
+else
+    echo "❌ Build failed with error code $?"
+    echo 
+    echo "Make sure GCC is installed:"
+    echo "  Ubuntu/Debian: sudo apt install build-essential"
+    echo "  CentOS/RHEL: sudo dnf install gcc"
+    echo "  macOS: xcode-select --install"
+    exit 1
+fi