Rebuild (Go 1.21+, no cgo needed, cross-compiles from Linux/Mac/Windows):
  GOOS=windows GOARCH=amd64 go build -ldflags "-H=windowsgui -s -w" -o ProjectionMapper.exe .
Layout: main.go (server, display list, launcher), platform_windows.go (monitor enumeration, borderless window placement),
web/ (the app: index.html, app.js, render.js, fx.js shaders, calib.js, seg.js, project.js, output.js), embedgz/ (AI model + onnxruntime wasm).
Dev run on any OS: PM_NO_BROWSER=1 PM_NO_EXIT=1 go run .   then open http://127.0.0.1:8137/
Tests used: work/test_math.js (node), headless Chrome scripts t1/t2/t3.js
