fix: resolve the cores handhelds rename

ArkOS ran the GBA with gpsp_ezode_mod and dArkOS with mgba_rumble: no
profile named them, so an install for the card's games kept every GBA
core's files, FBNeo's 3,472 data files among them. Each rename proven
from the OS build (same code base, same BIOS loading) joins its
profile's cores. The resolver folds either separator, and falls back to
the emulator column when the core names a mode, a machine or a plugin
of that program, only where its profile declares the folder's system:
MAME documents no GameKing ROM. 109 unresolved names are 56, each one
recorded with why in tests/test_games_index.py.

scripts/generate_games_index.py

@@ -294,6 +294,36 @@ def resolve_folder(
     return Resolution(sorted({resolver.canonical(s) for s in own}), f"systems of {profile}")
 
 
+# The emulator column of a row names the frontend or a launch mode, never
+# a program whose files are read: these never answer for a core.
+_NOT_PROGRAMS = frozenset({"retroarch", "retroarch32", "libretro", "external", "standalone",
+                           "port", "ports", "native", "sh", "os-shell", "none"})
+
+
+def emulator_profile(row: dict, platform: str, cores: ProfileResolver,
+                     resolver: SystemResolver, profiles: Profiles) -> str | None:
+    """The profile of the program a row's emulator column names, when its
+    core column names a mode, a machine or a plugin of that program: RetroBat
+    runs demul for core hikaru, AmberELEC MAME for core gamate, Batocera
+    mupen64plus for core glide64mk2.
+
+    Kept only when that profile declares a system of the folder: MAME's
+    profile has no GameKing, and answering MAME for its folder would leave
+    out the ROM the core needs. Unresolved, the folder keeps the files of
+    every core of its systems, as it did.
+    """
+    emulator = str(row.get("emulator") or "").strip()
+    if not emulator or emulator.lower() in _NOT_PROGRAMS or emulator.lower().startswith("standalone"):
+        return None
+    candidate = cores.resolve(emulator)
+    if not candidate:
+        return None
+    systems = resolver.resolve(folder_names(row), platform).systems
+    own = {str(s) for s in profiles.profiles.get(candidate, {}).get("systems") or []}
+    declared = {spelling for sid in own for spelling in resolver.equivalents(sid)}
+    return candidate if any(resolver.equivalents(sid) & declared for sid in systems) else None
+
+
 def build_setups(
     setups: dict[str, dict],
     resolver: SystemResolver,
@@ -321,7 +351,8 @@ def build_setups(
         counts = {"folders": 0, "resolved": 0, "profile": 0, "fallback": 0}
         for row in doc.get("folders", []):
             counts["folders"] += 1
-            profile = cores.resolve(row.get("core"))
+            profile = (cores.resolve(row.get("core"))
+                       or emulator_profile(row, platform, cores, resolver, profiles))
             resolution = resolve_folder(row, platform, profile, resolver, profiles, arcade)
             published: dict = {
                 "folder": row["folder"],

scripts/romfolders.py

@@ -172,7 +172,10 @@ class ProfileResolver:
             return None
         # RetroPie names a libretro package lr-<core> (scriptmodules/libretrocores).
         bare = core.removeprefix("lr-")
-        spellings = (core, core.lower(), bare, bare.replace("-", "_"), bare.lower().replace("-", "_"))
+        # Either separator in either direction: plumOS names flycast_xtreme
+        # the core flycast2021 lists as flycast-xtreme.
+        spellings = (core, core.lower(), bare, bare.replace("-", "_"), bare.lower().replace("-", "_"),
+                     bare.replace("_", "-"), bare.lower().replace("_", "-"))
         for name in dict.fromkeys(spellings):
             found = preferred_profile(self.index, name)
             if found: