Add beta channel info to about window

To avoid confusion for users on beta channel when the latest released version is a non-beta version.

electron/main/about.js

@@ -1,6 +1,8 @@
 import { join } from 'node:path'
 import { app, BrowserWindow, nativeTheme } from 'electron'
+
 import { win } from "./index"
+import CONFIG from "../config"
 
 let aboutWindow = null;
 
@@ -31,10 +33,15 @@ export function openAboutWindow() {
             aboutWindow.loadFile(join(process.env.DIST, 'about.html'))
         }
 
+        let versionString = app.getVersion()
+        if (CONFIG.get("settings.allowBetaVersions")) {
+            versionString += " (beta channel)"
+        }
+
         // don't show until content is loaded
         aboutWindow.webContents.on("did-finish-load", () => {
             aboutWindow.webContents.send("init", {
-                "version": app.getVersion(),
+                "version": versionString,
             });
             aboutWindow.show()
         })