fix: break circular import in horse racing commands

Extract shared.py from commands/__init__.py to break circular dependency:
- shared.py: shared variables/services/helper functions
- access.py: get_scope/check_access/get_event_id (canonical source)
- __init__.py: re-exports from shared.py for backward compat
- register/bet/race/help: import from .shared instead of package

danding_bot/plugins/group_horse_racing/commands/race.py

@@ -1,15 +1,17 @@
 import asyncio
 from nonebot import on_command
-from nonebot.adapters.onebot.v11 import Bot, Event
-from . import (
+from nonebot.adapters.onebot.v11 import Bot, Event, GroupMessageEvent
+from .shared import (
     room_store, race_engine, config, logger,
     get_scope, check_access, get_event_id,
     _send_to_scope, _build_race_image_message,
+    _get_user_name, _get_horses_in_order, _format_horse_label,
     run_race_with_settlement, points_service,
 )
 from ..models import RoomState, HorseState
-from nonebot.adapters.onebot.v11 import GroupMessageEvent
-from ..models import RoomState
+
+race_list_cmd = on_command("赛马列表", priority=5)
+
 
 @race_list_cmd.handle()
 async def handle_race_list(bot: Bot, event: Event):
@@ -61,7 +63,6 @@ async def handle_start(bot: Bot, event: Event):
             await start_cmd.finish("至少需要2匹马才能开赛")
             return
 
-        # 开赛权限限制：仅参赛者或群管理员可手动开赛（满8匹自动开赛不受影响）
         is_participant = user_id in [h.owner_id for h in room.horses.values()]
         is_admin = False
         if isinstance(event, GroupMessageEvent):
@@ -79,13 +80,11 @@ async def handle_start(bot: Bot, event: Event):
             await start_cmd.finish("只有参赛者或群管理员可以开赛")
             return
 
-        # Set all horses to racing state
         for horse in room.horses.values():
             horse.state = HorseState.RACING
 
     await start_cmd.send("比赛开始！")
 
-    # Run race in background (outside command handler)
     task = asyncio.create_task(run_race_with_settlement(bot, room, scope))
     race_engine.register_task(scope, task)
 
@@ -114,7 +113,6 @@ async def handle_cancel_race(bot: Bot, event: Event):
             await cancel_race_cmd.finish("当前没有进行中的比赛")
             return
 
-        # 权限：只有参赛者或群管理员可以取消
         is_participant = user_id in [h.owner_id for h in room.horses.values()]
         is_admin = False
         if isinstance(event, GroupMessageEvent):
@@ -132,31 +130,22 @@ async def handle_cancel_race(bot: Bot, event: Event):
             await cancel_race_cmd.finish("只有参赛者或群管理员可以取消比赛")
             return
 
-        # 停止后台比赛任务
         race_engine.stop_race(scope)
 
-        # 退还所有下注积分
         total_refund = 0
-        for bet in room.bets[:]:  # 遍历副本
+        for bet in room.bets[:]:
             success, _ = await points_service.refund_bet_points(
-                bet.user_id, bet.amount, "比赛取退还下注"
+                bet.user_id, bet.amount, "比赛取消退还下注"
             )
             if success:
                 total_refund += bet.amount
 
-        # 清空下注记录
         room.bets.clear()
 
-        # 重置马匹状态为等待
         for horse in room.horses.values():
             horse.state = HorseState.WAITING
 
-        # 重置房间状态
         room.state = RoomState.WAITING
         room.tick_count = 0
 
-    await _send_to_scope(scope, f"🏇 比赛已取消！共退还 {total_refund} 积分。")
-
-help_cmd = on_command("赛马帮助", priority=5)
-
-
+    await _send_to_scope(bot, scope, f"🏇 比赛已取消！共退还 {total_refund} 积分。")