feat: read recalbox's cores from its system files

es_bios.xml names only the cores that need a BIOS, so a hand-kept
registry list stood in, with mame and mamemess that Recalbox does not
ship and without vice, ymir, vircon32 and others it does. The scraper
now reads each system.ini of recalbox-romfs2 at the scraped tag, and
the registry list is gone.

tests/test_scraper_contract.py

@@ -219,23 +219,45 @@ class RetroPiePackageList(unittest.TestCase):
 
 
 class RecalboxBuildMode(unittest.TestCase):
-    """es_bios.xml names a libretro core as libretro/<name> and a standalone
-    emulator by its bare name: the prefix is the build mode, and a platform
-    that runs an emulator standalone must say so or the pack lays its files
-    out for the libretro build."""
+    """Recalbox's cores come from each system.ini of recalbox-romfs2: a
+    `[core.N]` section names `emulator = "libretro"` with the core, or a
+    standalone emulator. es_bios.xml only names the cores that need a BIOS,
+    so read alone it left most of Recalbox's cores, mame0258 and mame0278
+    among them, outside the pack."""
 
-    def test_bare_names_are_the_standalone_emulators(self):
-        from scraper.recalbox_scraper import split_cores
+    SYSTEM_INI = """\
+[system]
+name = "mame"
+fullname = "MAME"
+  extra line the parser must survive.
 
-        cores, standalone = split_cores(
-            ["libretro/uae", "amiberry", "", "dolphin", "libretro/dolphin", "libretro-hatari", "hatari"]
-        )
-        self.assertEqual(
-            cores,
-            ["amiberry", "dolphin", "hatari", "libretro-hatari", "libretro/dolphin", "libretro/uae"],
-        )
-        self.assertEqual(standalone, ["amiberry", "dolphin", "hatari"])
+[core.0]
+package = BR2_PACKAGE_LIBRETRO_MAME0278
+emulator = "libretro"
+core = "mame0278"
 
+[core.1]
+emulator = "advancemame"
+core = "advancemame"
+
+[core.2.rpi4]
+emulator = "libretro"
+core = "mame2003_plus"
+"""
+
+    def test_libretro_cores_and_standalone_emulators(self):
+        from scraper.recalbox_scraper import system_ini_cores
+
+        cores, standalone = system_ini_cores(self.SYSTEM_INI)
+        self.assertEqual(cores, {"mame0278", "advancemame", "mame2003_plus"})
+        self.assertEqual(standalone, {"advancemame"})
+
+    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"]["recalbox"])
 
 
 class UnreadableReleaseStopsTheScrape(unittest.TestCase):