fix: 修复数据库导入错误

- 修复12处从错误位置导入get_db_session/get_engine的问题
- 函数应从core导入，模型应从core.models导入
- 修复bot.py使用check_and_migrate_database代替不存在的initialize_database

影响文件：
- bot.py: 使用正确的初始化函数
- schedule_manager.py: 修复get_db_session导入
- relationship_service.py: 修复get_db_session导入
- schedule_api.py: 修复get_db_session导入
- utils.py (llm_models): 修复get_db_session导入
- utils_image.py: 修复get_db_session导入
- utils_video.py: 修复get_db_session导入
- user_ban.py: 修复get_db_session导入
- statistics.py: 修复get_db_session导入
- storage.py: 修复get_db_session导入
- anti_injector.py: 修复2处get_db_session导入
- permission_manager.py: 修复get_engine导入

src/plugin_system/apis/schedule_api.py

@@ -52,7 +52,8 @@ from typing import Any
 import orjson
 from sqlalchemy import func, select
 
-from src.common.database.core.models import MonthlyPlan, Schedule, get_db_session
+from src.common.database.core.models import MonthlyPlan, Schedule
+from src.common.database.core import get_db_session
 from src.common.logger import get_logger
 from src.schedule.database import get_active_plans_for_month
 

src/plugin_system/core/permission_manager.py

@@ -10,7 +10,8 @@ from sqlalchemy import delete, select
 from sqlalchemy.exc import IntegrityError, SQLAlchemyError
 from sqlalchemy.ext.asyncio import async_sessionmaker
 
-from src.common.database.core.models import PermissionNodes, UserPermissions, get_engine
+from src.common.database.core.models import PermissionNodes, UserPermissions
+from src.common.database.core import get_engine
 from src.common.logger import get_logger
 from src.config.config import global_config
 from src.plugin_system.apis.permission_api import IPermissionManager, PermissionNode, UserInfo

src/plugin_system/services/relationship_service.py

@@ -5,7 +5,8 @@
 
 import time
 
-from src.common.database.core.models import UserRelationships, get_db_session
+from src.common.database.core.models import UserRelationships
+from src.common.database.core import get_db_session
 from src.common.logger import get_logger
 from src.config.config import global_config