Reorganize source tree and build assets

scripts/build-windows.bat

@@ -0,0 +1,29 @@
+@echo off
+setlocal enabledelayedexpansion
+
+set "OUTPUT=%~1"
+if "%OUTPUT%"=="" set "OUTPUT=dist\windows\pysentry.exe"
+
+set "GOEXE=%ProgramFiles%\Go\bin\go.exe"
+if not exist "%GOEXE%" set "GOEXE=go"
+
+if exist "C:\msys64\ucrt64\bin" set "PATH=C:\msys64\ucrt64\bin;%PATH%"
+
+set "CGO_ENABLED=1"
+set "GOOS=windows"
+set "GOARCH=amd64"
+
+for %%I in ("%OUTPUT%") do set "OUTDIR=%%~dpI"
+if not exist "%OUTDIR%" mkdir "%OUTDIR%"
+
+where windres.exe >nul 2>nul
+if %ERRORLEVEL%==0 (
+    windres.exe -O coff -o cmd\pysentry\rsrc_windows_amd64.syso packaging\windows\pysentry.rc
+)
+
+"%GOEXE%" build -trimpath -ldflags "-s -w" -o "%OUTPUT%" .\cmd\pysentry
+if errorlevel 1 exit /b 1
+
+xcopy /E /I /Y assets "%OUTDIR%assets" >nul
+
+echo Built %OUTPUT%