feat: list retrodeck standalone emulators

scripts/scraper/retrodeck_scraper.py

@@ -442,6 +442,9 @@ class Scraper(BaseScraper):
             "hash_type": "md5",
             "verification_mode": "md5",
             "cores": cores,
+            # Each component is one emulator RetroDECK ships and launches on
+            # its own; retroarch is the one that runs cores.
+            "standalone_cores": [c for c in cores if c != "retroarch"],
             "systems": systems,
         }