Refactor convert to group chat to new popup

public/script.js

@@ -8553,7 +8553,7 @@ async function doImpersonate(args, prompt) {
 
 async function doNewChat({ deleteCurrentChat = false } = {}) {
     //Make a new chat for selected character
-    if ((!selected_group && this_chid == undefined) || menu_type != 'create') {
+    if ((!selected_group && this_chid == undefined) || menu_type == 'create') {
         return;
     }
 

public/scripts/bookmarks.js

@@ -24,6 +24,7 @@ import {
     saveGroupBookmarkChat,
     selected_group,
 } from './group-chats.js';
+import { Popup } from './popup.js';
 import { createTagMapFromList } from './tags.js';
 
 import {
@@ -239,8 +240,7 @@ async function convertSoloToGroupChat() {
         return;
     }
 
-    const confirm = await callPopup('Are you sure you want to convert this chat to a group chat?', 'confirm');
-
+    const confirm = await Popup.show.confirm('Convert to group chat', 'Are you sure you want to convert this chat to a group chat?<br />This cannot be reverted.');
     if (!confirm) {
         return;
     }

public/scripts/popup.js

@@ -78,8 +78,8 @@ const showPopupHelper = {
     /**
      * Asynchronously displays a confirmation popup with the given header and text, returning the clicked result button value.
      *
-     * @param {string} header - The header text for the popup.
-     * @param {string} text - The main text for the popup.
+     * @param {string?} header - The header text for the popup.
+     * @param {string?} text - The main text for the popup.
      * @param {PopupOptions} [popupOptions={}] - Options for the popup.
      * @return {Promise<POPUP_RESULT>} A Promise that resolves with the result of the user's interaction.
      */
@@ -491,9 +491,17 @@ export class Popup {
 }
 
 class PopupUtils {
+    /**
+     * Builds popup content with header and text below
+     *
+     * @param {string} header - The header to be added to the text
+     * @param {string} text - The main text content
+     */
     static BuildTextWithHeader(header, text) {
-        return `
-            <h3>${header}</h1>
+        if (!header) {
+            return text;
+        }
+        return `<h3>${header}</h3>
             ${text}`;
     }
 }