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/api/response.py

@@ -0,0 +1,75 @@
+"""
+API Response Wrapper
+统一 API 响应格式
+"""
+from datetime import datetime
+from typing import Any, Generic, List, Optional, TypeVar
+from uuid import UUID
+from pydantic import BaseModel, ConfigDict, Field
+
+T = TypeVar("T")
+
+
+class ApiResponse(BaseModel, Generic[T]):
+    """统一 API 响应格式"""
+    model_config = ConfigDict(from_attributes=True)
+
+    success: bool = True
+    message: str = "Success"
+    data: Optional[T] = None
+    error: Optional[dict] = None
+    timestamp: datetime = Field(default_factory=datetime.utcnow)
+
+    @classmethod
+    def ok(cls, data: T = None, message: str = "Success") -> "ApiResponse[T]":
+        """成功响应"""
+        return cls(success=True, message=message, data=data)
+
+    @classmethod
+    def fail(cls, message: str, error: dict = None) -> "ApiResponse[None]":
+        """失败响应"""
+        return cls(success=False, message=message, error=error)
+
+
+class PaginatedResponse(BaseModel, Generic[T]):
+    """分页响应格式"""
+    model_config = ConfigDict(from_attributes=True)
+
+    success: bool = True
+    message: str = "Success"
+    data: List[T] = []
+    pagination: dict = Field(default_factory=lambda: {
+        "page": 1,
+        "page_size": 20,
+        "total": 0,
+        "total_pages": 0
+    })
+
+    @classmethod
+    def ok(
+        cls,
+        items: List[T],
+        page: int = 1,
+        page_size: int = 20,
+        total: int = 0
+    ) -> "PaginatedResponse[T]":
+        """创建分页响应"""
+        total_pages = (total + page_size - 1) // page_size if page_size > 0 else 0
+        return cls(
+            success=True,
+            data=items,
+            pagination={
+                "page": page,
+                "page_size": page_size,
+                "total": total,
+                "total_pages": total_pages
+            }
+        )
+
+
+class ErrorDetail(BaseModel):
+    """错误详情"""
+    code: str
+    message: str
+    details: Optional[dict] = None
+    field: Optional[str] = None