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.

pkg/logger.py

@@ -0,0 +1,75 @@
+"""
+日志配置模块
+
+负责配置 loguru 和接管标准库的日志
+"""
+
+import sys
+import logging
+from loguru import logger
+
+
+class InterceptHandler(logging.Handler):
+    """
+    拦截标准库的日志并转发到 loguru
+    """
+    def emit(self, record: logging.LogRecord) -> None:
+        # 获取对应的 loguru 级别
+        try:
+            level = logger.level(record.levelname).name
+        except ValueError:
+            level = record.levelno
+
+        # 查找调用者的帧
+        frame, depth = logging.currentframe(), 2
+        while frame.f_code.co_filename == logging.__file__:
+            frame = frame.f_back
+            depth += 1
+
+        logger.opt(depth=depth, exception=record.exc_info).log(level, record.getMessage())
+
+
+def setup_logging(debug: bool = False) -> None:
+    """
+    配置日志系统
+    
+    :param debug: 是否启用调试模式
+    """
+    # 配置 loguru
+    # 移除默认的 handler
+    logger.remove()
+
+    # 根据 DEBUG 模式配置不同的日志级别和格式
+    if debug:
+        logger.add(
+            sys.stderr,
+            level="DEBUG"
+        )
+    else:
+        logger.add(
+            sys.stderr,
+            level="INFO"
+        )
+
+    # 接管 uvicorn 的日志
+    logging.getLogger("uvicorn").handlers = [InterceptHandler()]
+    logging.getLogger("uvicorn.access").handlers = [InterceptHandler()]
+    logging.getLogger("uvicorn.error").handlers = [InterceptHandler()]
+
+    # 接管 SQLAlchemy 的日志
+    logging.getLogger("sqlalchemy.engine").handlers = [InterceptHandler()]
+    logging.getLogger("sqlalchemy.pool").handlers = [InterceptHandler()]
+
+    # 设置日志级别
+    if debug:
+        logging.getLogger("uvicorn").setLevel(logging.DEBUG)
+        logging.getLogger("uvicorn.access").setLevel(logging.DEBUG)
+        logging.getLogger("uvicorn.error").setLevel(logging.DEBUG)
+        logging.getLogger("sqlalchemy.engine").setLevel(logging.INFO)
+        logging.getLogger("sqlalchemy.pool").setLevel(logging.DEBUG)
+    else:
+        logging.getLogger("uvicorn").setLevel(logging.INFO)
+        logging.getLogger("uvicorn.access").setLevel(logging.WARNING)
+        logging.getLogger("uvicorn.error").setLevel(logging.WARNING)
+        logging.getLogger("sqlalchemy.engine").setLevel(logging.WARNING)
+        logging.getLogger("sqlalchemy.pool").setLevel(logging.WARNING)