sources: Add user-facing name constant

cartridges/sources/__init__.py

@@ -5,7 +5,7 @@ import os
 import sys
 from collections.abc import Generator, Iterable
 from pathlib import Path
-from typing import Protocol
+from typing import Final, Protocol
 
 from gi.repository import GLib
 
@@ -28,7 +28,8 @@ OPEN = (
 class Source(Protocol):
     """A source of games to import."""
 
-    ID: str
+    ID: Final[str]
+    NAME: Final[str]
 
     @staticmethod
     def get_games(*, skip_ids: Iterable[str]) -> Generator[Game]:

cartridges/sources/steam.py

@@ -9,6 +9,7 @@ import struct
 import time
 from collections.abc import Generator, Iterable, Sequence
 from contextlib import suppress
+from gettext import gettext as _
 from os import SEEK_CUR
 from pathlib import Path
 from typing import Any, BinaryIO, NamedTuple, Self, cast
@@ -19,7 +20,7 @@ from cartridges.games import Game
 
 from . import APPLICATION_SUPPORT, DATA, FLATPAK, OPEN, PROGRAM_FILES_X86
 
-ID: str = "steam"
+ID, NAME = "steam", _("Steam")
 
 _DATA_PATHS = (
     Path.home() / ".steam" / "steam",