feat(backend): 添加核心架构模块

- 添加认证模块 (auth.py)
- 添加 CRUD 基础操作 (crud.py)
- 添加异常处理 (exceptions.py)
- 添加日志模块 (logging.py)
- 添加响应格式 (response.py)
- 添加依赖注入 (dependencies.py)

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

backend/app/core/logging.py

@@ -0,0 +1,66 @@
+"""
+Logging Configuration
+日志配置
+"""
+import logging
+import sys
+from typing import Any
+from logging.handlers import RotatingFileHandler
+from pathlib import Path
+from app.core.config import get_settings
+
+settings = get_settings()
+
+# Log directory
+LOG_DIR = Path("./logs")
+LOG_DIR.mkdir(exist_ok=True)
+
+
+def setup_logging(name: str = "yg_dataset") -> logging.Logger:
+    """Setup application logging"""
+    logger = logging.getLogger(name)
+    logger.setLevel(logging.DEBUG if settings.DEBUG else logging.INFO)
+
+    # Avoid duplicate handlers
+    if logger.handlers:
+        return logger
+
+    # Console handler
+    console_handler = logging.StreamHandler(sys.stdout)
+    console_handler.setLevel(logging.DEBUG if settings.DEBUG else logging.INFO)
+    console_formatter = logging.Formatter(
+        fmt="%(asctime)s | %(levelname)-8s | %(name)s:%(funcName)s:%(lineno)d | %(message)s",
+        datefmt="%Y-%m-%d %H:%M:%S"
+    )
+    console_handler.setFormatter(console_formatter)
+    logger.addHandler(console_handler)
+
+    # File handler
+    file_handler = RotatingFileHandler(
+        LOG_DIR / f"{name}.log",
+        maxBytes=10 * 1024 * 1024,  # 10MB
+        backupCount=5,
+        encoding="utf-8"
+    )
+    file_handler.setLevel(logging.INFO)
+    file_formatter = logging.Formatter(
+        fmt="%(asctime)s | %(levelname)-8s | %(name)s:%(funcName)s:%(lineno)d | %(message)s",
+        datefmt="%Y-%m-%d %H:%M:%S"
+    )
+    file_handler.setFormatter(file_formatter)
+    logger.addHandler(file_handler)
+
+    return logger
+
+
+# Create default logger
+logger = setup_logging()
+
+
+class LoggerMixin:
+    """Mixin to add logging capability to classes"""
+
+    @property
+    def log(self) -> logging.Logger:
+        """Get logger for this class"""
+        return logging.getLogger(self.__class__.__module__ + "." + self.__class__.__name__)