run the following code in the console and it will prevent you from disconnecting.

function ClickConnect(){
    console.log("Working"); 
    document.querySelector("colab-toolbar-button#connect").click() 
setInterval(ClickConnect,60000)
Also this can be done by
function ColabReconnect() {
    var dialog = document.querySelector("colab-dialog.yes-no-dialog");
    var dialogTitle = dialog && dialog.querySelector("div.content-area>h2");
    if (dialogTitle && dialogTitle.innerText == "Runtime disconnected") {
        dialog.querySelector("paper-button#ok").click();
        console.log("Reconnecting...");
    } else {
        console.log("ColabReconnect is in service.");
timerId = setInterval(ColabReconnect, 60000);
Another and better thing instead of clicking the connect button is click on comment button to keep my session alive
function ClickConnect(){
console.log("Working"); 
document.querySelector("#comments > span").click() 
setInterval(ClickConnect,5000)
Another creative option is to keep clicking "Refresh folder" in the file explorer pane
function ClickRefresh(){
  console.log("Working"); 
  document.querySelector("[icon='colab:folder-refresh']").click()
const myjob = setInterval(ClickRefresh, 60000)