修复：group_horse_racing 环境变量加载问题

- 修改 __init__.py 在插件初始化时加载 Config
- 修改 commands.py 和 test_commands.py 从 __init__.py 导入 plugin_config
- 确保配置通过 NoneBot 的 driver 正确加载环境变量
- 这样可以正确解析 .env 中的 JSON 格式环境变量

这解决了权限检查中 TESTERS 集合为空的问题。

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

danding_bot/plugins/group_horse_racing/commands.py

@@ -1,14 +1,15 @@
 from nonebot import on_command
 from nonebot.adapters.onebot.v11 import Bot, Event, GroupMessageEvent, PrivateMessageEvent
 
-from .config import Config
 from .room_store import RoomStore
 from .points_service import PointsService
 from .race_engine import RaceEngine
 from .message_service import MessageService
 from .models import Room, Horse, Bet, HorseState
 
-config = Config()
+# Import config from __init__ to ensure it's loaded through NoneBot driver
+from . import plugin_config as config
+
 room_store = RoomStore(config)
 points_service = PointsService(config)
 race_engine = RaceEngine(config)