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/services/app-state-service/AppStateService.ts

@@ -46,10 +46,12 @@ export async function setLastLoadedRundown(rundownKey: string): Promise<void> {
   await config.write();
 }
 
-export async function getShowWelcomeDialog(): Promise<boolean> {
+export async function getShowWelcomeDialog(restorePointExists: boolean): Promise<boolean> {
   // in test environment, we do not want the dialog
   if (isTest) return false;
 
+  if (restorePointExists) return false;
+
   await config.read();
   return config.data.showWelcomeDialog ?? true; // default to  true
 }