feat(backend): 更新 API 支持语义分割和 embedding 配置

- chunks API 添加 embedding 配置字段
- projects API 更新路由和方法

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

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

@@ -2,6 +2,8 @@
 Projects API Router
 """
 import logging
+import shutil
+from pathlib import Path
 from typing import List, Optional
 from uuid import UUID
 from fastapi import APIRouter, Depends, Query
@@ -107,5 +109,12 @@ async def delete_project(
     logger.info(f"Deleting project: id={project_id}")
     await project_crud.get_or_raise(db, project_id, "Project")
     await project_crud.delete(db, project_id)
+
+    # 删除项目对应的本地数据目录
+    project_data_dir = Path("/data/code/YG-Datasets/data") / str(project_id)
+    if project_data_dir.exists():
+        shutil.rmtree(project_data_dir)
+        logger.info(f"Project data directory deleted: {project_data_dir}")
+
     logger.info(f"Project deleted: id={project_id}")
     return ApiResponse.ok(message="Project deleted successfully")