fix: let retrodeck's components name its cores

The registry list added clk and gsplus, which RetroDECK does not ship
as components, current or archived, and overrode the list the scraper
reads from the component manifests.

platforms/_registry.yml

@@ -306,28 +306,6 @@ platforms:
       - username: monster-penguin
         contribution: platform support
         pr: 36
-    cores:
-    - azahar
-    - cemu
-    - clk
-    - dolphin
-    - duckstation
-    - gsplus
-    - gzdoom
-    - mame
-    - melonds
-    - openbor
-    - pcsx2
-    - pico-8
-    - ppsspp
-    - primehack
-    - retroarch
-    - rpcs3
-    - ruffle
-    - solarus
-    - vita3k
-    - xemu
-    - xroar
     target_scraper: null
     target_source: null
     install:

tests/test_scraper_contract.py

@@ -295,6 +295,42 @@ class RetroBatCoresFromItsES(unittest.TestCase):
         self.assertIn("snes9x", platform["cores"])
 
 
+class RocknixRunsItsStandaloneEmulators(unittest.TestCase):
+    """ROCKNIX declared all_libretro while it packages duckstation, dolphin,
+    ppsspp and 33 other emulators standalone, and read rocknix-systems on
+    the next branch under the release's version."""
+
+    def test_package_names_reach_the_profiles(self):
+        from scraper.rocknix_scraper import standalone_emulators
+
+        self.assertEqual(
+            standalone_emulators(["duckstation-sa", "hatarisa", "openbor"]),
+            ["duckstation", "duckstation-sa", "hatari", "hatarisa", "openbor"],
+        )
+
+    def test_the_platform_file_is_read_at_its_release(self):
+        import yaml
+
+        root = Path(__file__).resolve().parents[1]
+        platform = yaml.safe_load((root / "platforms" / "rocknix.yml").read_text())
+        self.assertIn(f"/distribution/{platform['version']}/", platform["source"])
+        self.assertIn("retroarch", platform["cores"])
+        registry = yaml.safe_load((root / "platforms" / "_registry.yml").read_text())
+        self.assertNotIn("cores", registry["platforms"]["rocknix"])
+
+
+class RetroDeckCoresAreItsComponents(unittest.TestCase):
+    """The registry added clk and gsplus to RetroDECK, which ships neither
+    as a component, current or archived."""
+
+    def test_the_registry_leaves_the_list_to_the_scraper(self):
+        import yaml
+
+        root = Path(__file__).resolve().parents[1]
+        registry = yaml.safe_load((root / "platforms" / "_registry.yml").read_text())
+        self.assertNotIn("cores", registry["platforms"]["retrodeck"])
+
+
 class UnreadableReleaseStopsTheScrape(unittest.TestCase):
     """A failed tag lookup fell back to master, or to an empty or invented
     version. BizHawk, RomM, Batocera and Recalbox then wrote a YAML read from