I'm sure I have see a way to close down Photoshop in a Photoshop script. I never had the need to. It may be a simple statement like app.close(); I don't know javascript and only hack Photoshop script mostly by looking at others code. app.close(); is a guess on my part. Let me try it. I was wrong its photoshop.quit();
So make your MoveToArchive.jsx look something like this
try{
var BAT = new File(Folder.temp + "/MoveFilesToArchive.bat");
BAT.open("w");
BAT.writeln('Copy /Y "c:\\Process\\*.jpg" "c:\\Archive\\*.*"');
BAT.writeln('Del "c:\Process\\*.jpg"');
BAT.close();
BAT.execute(); // execute the temp bat file
}catch(e){
alert("Bat MoveFilesToArchive failed to execute.");
};
photoshop.quit();