feat: Enhance file management and user features

- Add file deduplication mechanism based on PhysicalFile reference counting.
- Implement chunked upload support for large files with resumable uploads.
- Update sharing page to automatically render README and preview content.
- Integrate Redis for caching and token storage (optional).
- Refactor project structure to include new models for download tasks, nodes, and tasks.
- Introduce user filtering parameters for admin user management.
- Add CORS middleware for handling cross-origin requests.
- Improve error messages for authentication failures.
- Update user model to include two-factor authentication key management.
- Enhance API documentation and response models for clarity.
- Implement admin checks for user management and permissions.

main.py

@@ -1,6 +1,7 @@
 from typing import NoReturn
 
 from fastapi import FastAPI, Request
+from fastapi.middleware.cors import CORSMiddleware
 
 from utils.conf import appmeta
 from utils.http.http_exceptions import raise_internal_error
@@ -33,6 +34,15 @@ app = FastAPI(
     openapi_url="/openapi.json" if appmeta.debug else None,
 )
 
+# 配置 CORS 中间件
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],  # 开发环境允许所有来源，生产环境应该限制为具体域名
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
 @app.exception_handler(Exception)
 async def handle_unexpected_exceptions(request: Request, exc: Exception) -> NoReturn:
     """