feat(xtream): add 'stop' property to EpgItem interface for enhanced program timing

src/app/xtream/epg-item.interface.ts

@@ -5,6 +5,7 @@ export interface EpgItem {
     lang: string;
     start: string;
     end: string;
+    stop: string;
     description: string;
     channel_id: string;
     start_timestamp: string;