feat(gui): add GUI (Test) implementation with documentation and admin support

- Add GUI (Test) module with Fyne-based interface (internal/gui/gui.go, internal/gui/server.go)
- Add CLI monitoring capability (internal/cli/monitor.go)
- Add main_cli.go entry point for CLI-only builds
- Add comprehensive documentation suite covering setup, build, quick start, and changelog
- Add admin manifest (admin.manifest) for Windows UAC elevation support
- Add rsrc.syso.json configuration for resource embedding
- Update .gitignore to exclude build scripts (*.bat, *.sh)
- Update main.go and cli.go to support dual GUI (Test)/CLI modes
- Update README.md with new project information
- Enables users to build and run both GUI (Test)and CLI versions with proper admin privileges on Windows

.gitignore

@@ -5,6 +5,8 @@ vpn-client.exe
 *.dll
 *.so
 *.dylib
+*.bat
+*.sh
 
 # Test binary
 *.test