Ship Windows plug-and-play host exe with USB wait and autostart.

Users no longer need Python: run.bat or install_autostart.ps1; agent reconnects when CYD is plugged in.

host/run.bat

@@ -0,0 +1,20 @@
+@echo off
+setlocal
+cd /d "%~dp0"
+
+rem Prefer frozen exe (no Python). Fallback to python for developers.
+if exist "%~dp0send_sysinfo.exe" (
+  start "CYD Server Info" "%~dp0send_sysinfo.exe" %*
+  exit /b 0
+)
+
+where python >nul 2>nul
+if %ERRORLEVEL%==0 (
+  start "CYD Server Info" python "%~dp0send_sysinfo.py" %*
+  exit /b 0
+)
+
+echo send_sysinfo.exe not found and Python missing.
+echo Build on a PC with Python:  powershell -File build_exe.ps1
+pause
+exit /b 1