feat(backend): 完善日志系统，支持按日期分目录存储

- 实现 logs/YYYY-MM-DD/ 日期文件夹结构
- 添加 success.log 和 failure.log 专用日志
- 使用 TimedRotatingFileHandler 实现按天切割
- 添加 log_success 和 log_failure 便捷函数
- 集成 markitdown 进行文件转换
- 优化文件存储路径，按项目ID分类存储

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

backend/app/api/v1/files/__init__.py

@@ -5,7 +5,7 @@ import os
 import asyncio
 from pathlib import Path
 from typing import Optional
-from uuid import UUID
+from uuid import UUID, uuid4
 from fastapi import APIRouter, Depends, UploadFile, File, Query
 from fastapi.responses import FileResponse
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -15,20 +15,31 @@ from app.core.config import get_settings
 from app.core.database import get_db
 from app.core.exceptions import ValidationException, NotFoundException
 from app.core.crud import CRUDBase
+from app.core.logging import log_success, log_failure
 from app.models.models import File as FileModel
 from app.schemas.file import FileResponse, FileCreateSchema
 
 settings = get_settings()
 router = APIRouter()
 
-# Ensure upload directory exists
-UPLOAD_DIR = Path(settings.UPLOAD_DIR)
-UPLOAD_DIR.mkdir(parents=True, exist_ok=True)
-
 # Initialize CRUD
 file_crud = CRUDBase(FileModel)
 
 
+def get_project_raw_dir(project_id: str) -> Path:
+    """获取项目的 raw 文件目录"""
+    base_dir = Path("/data/code/YG-Datasets/data") / project_id / "raw"
+    base_dir.mkdir(parents=True, exist_ok=True)
+    return base_dir
+
+
+def get_project_ready_dir(project_id: str) -> Path:
+    """获取项目的 ready 文件目录（处理后的文件）"""
+    base_dir = Path("/data/code/YG-Datasets/data") / project_id / "ready"
+    base_dir.mkdir(parents=True, exist_ok=True)
+    return base_dir
+
+
 def get_file_type(filename: str) -> str:
     """Get file type from extension"""
     ext = filename.rsplit('.', 1)[-1].lower() if '.' in filename else ''
@@ -82,40 +93,62 @@ async def upload_file(
     db: AsyncSession = Depends(get_db)
 ):
     """Upload a file"""
-    # Read file content for validation
-    content = await file.read()
-    file_size = len(content)
+    try:
+        # Read file content for validation
+        content = await file.read()
+        file_size = len(content)
 
-    # Validate file
-    validate_file(file.filename, file_size)
+        # Validate file
+        validate_file(file.filename, file_size)
 
-    # Save file to disk
-    safe_filename = f"{project_id}_{UUID.uuid4().hex[:8]}_{file.filename}"
-    file_path = UPLOAD_DIR / safe_filename
+        # Save file to disk - 使用项目 raw 目录
+        safe_filename = f"{uuid4().hex[:8]}_{file.filename}"
+        project_dir = get_project_raw_dir(str(project_id))
+        file_path = project_dir / safe_filename
 
-    # Write file asynchronously
-    await asyncio.get_event_loop().run_in_executor(
-        None,
-        lambda: file_path.write_bytes(content)
-    )
+        # Write file asynchronously
+        await asyncio.get_event_loop().run_in_executor(
+            None,
+            lambda: file_path.write_bytes(content)
+        )
 
-    # Create file record
-    db_file = FileModel(
-        project_id=project_id,
-        filename=file.filename,
-        file_type=get_file_type(file.filename),
-        file_path=str(file_path),
-        size=file_size,
-        status="pending"
-    )
-    db.add(db_file)
-    await db.commit()
-    await db.refresh(db_file)
+        # Create file record
+        db_file = FileModel(
+            project_id=project_id,
+            filename=file.filename,
+            file_type=get_file_type(file.filename),
+            file_path=str(file_path),
+            size=file_size,
+            status="pending"
+        )
+        db.add(db_file)
+        await db.commit()
+        await db.refresh(db_file)
 
-    return ApiResponse.ok(
-        data={"id": str(db_file.id), "filename": db_file.filename, "status": db_file.status},
-        message="File uploaded successfully"
-    )
+        # 记录成功日志
+        log_success(
+            "文件上传成功",
+            project_id=str(project_id),
+            file_id=str(db_file.id),
+            filename=file.filename,
+            file_type=db_file.file_type,
+            file_size=file_size,
+            file_path=str(file_path)
+        )
+
+        return ApiResponse.ok(
+            data={"id": str(db_file.id), "filename": db_file.filename, "status": db_file.status},
+            message="File uploaded successfully"
+        )
+    except Exception as e:
+        # 记录失败日志
+        log_failure(
+            "文件上传失败",
+            project_id=str(project_id),
+            filename=file.filename if 'file' in locals() else "unknown",
+            error=str(e)
+        )
+        raise
 
 
 @router.get("", response_model=ApiResponse)