Refactor config, logging, and startup structure

Introduced pkg modules for environment config, logging, and startup initialization. Replaced direct config and logging setup in main.py with modularized functions. Updated database and migration modules to use environment variables and improved DEBUG handling. Removed tool.py and migrated password utilities to pkg. Cleaned up legacy comments and unused code in models and routes.

routes/session.py

@@ -6,7 +6,7 @@ from fastapi.security import OAuth2PasswordRequestForm
 from fastapi import APIRouter
 import jwt, JWT
 from sqlmodel.ext.asyncio.session import AsyncSession
-from pkg.password import Password
+from pkg import Password
 from loguru import logger
 
 from model.token import Token