feat: add a --no-game-data pack narrowing

The install manifest marks each game data file "category": "game_data":
a platform entry only game data profile entries read, or a core file its
profile declares game data. Firmware carries no category. Every manifest
says "categorized": true so the installer can refuse an older list.

generate_pack.py --no-game-data cuts those files from the platform list
and the core profiles before the build, names each one with the cores that
read it as game data, and tags the pack _NoGameData through _narrowings.
verify.py and the pack check take the same cut, so --verify-packs and the
report describe the pack the builder wrote. Modes without a platform
(--emulator, --system alone, --from-md5) and --all-variants refuse it.

scripts/packverify.py

@@ -32,6 +32,7 @@ from nativemode import reads_file_contents
 import region as region_mod
 from packresolve import resolve_file
 from exporter.candidates import BIOS, EntryCategories
+from gamedata import without_game_data
 from common import resolve_platform_cores
 from common import sanitize_pack_path
 import zipfile
@@ -634,6 +635,7 @@ def verify_pack_against_platform(
     target_cores: set[str] | None = None,
     source: str = "full",
     required_only: bool = False,
+    no_game_data: bool = False,
 ) -> tuple[bool, int, int, list[str], int, int, int, int, int, int]:
     """Verify a pack ZIP against its platform config and core requirements.
 
@@ -644,6 +646,8 @@ def verify_pack_against_platform(
     ``required_only`` are the variant the pack was built as: a platform-only
     pack is held to the platform's list alone, a truth pack to the cores'
     files alone, and a required-only pack to the required entries of both.
+    ``no_game_data`` holds the pack to the firmware alone, cut as the
+    builder cuts it.
 
     Checks:
     1. Every baseline file declared by the platform exists in the ZIP
@@ -657,7 +661,7 @@ def verify_pack_against_platform(
     baseline_present, core_checked, core_present, baseline_excluded,
     baseline_absent)``. ``baseline_absent`` counts destinations the collection
     holds no file for that are a game's data or that no core the platform
-    runs opens; verify.py counts them apart from firmware.
+    runs opens. verify.py counts them apart from firmware.
     """
 
     config = load_platform_config(platform_name, platforms_dir)
@@ -668,6 +672,9 @@ def verify_pack_against_platform(
 
     if emu_profiles is None:
         emu_profiles = load_emulator_profiles(emulators_dir)
+    if no_game_data:
+        cut = without_game_data(config, emu_profiles, data_registry, target_cores)
+        config, emu_profiles = cut.config, cut.profiles
 
     expected_systems = config.get("systems", {})
     if target_cores is not None: