refactor: move welcome modal logic to AppStateService

The logic for deciding whether to show the welcome modal has been moved from `app.ts` to `AppStateService.ts`. The `getShowWelcomeDialog` function now accepts a boolean indicating whether a restore point exists and returns `false` if it does. This keeps the business logic out of the main application file and in the relevant service.

apps/server/src/app.ts

@@ -184,10 +184,7 @@ export const startServer = async (): Promise<{ message: string; serverPort: numb
   // the express server must be started before the socket otherwise the on error event listener will not attach properly
   const resultPort = await serverTryDesiredPort(expressServer, desiredPort);
   await getDataProvider().setSettings({ ...settings, serverPort: resultPort });
-  let showWelcome = await getShowWelcomeDialog();
-  if (restorePoint) {
-    showWelcome = false;
-  }
+  const showWelcome = await getShowWelcomeDialog(!!restorePoint);
 
   socket.init(expressServer, showWelcome, prefix);