7b21a69ceb
Replaced synchronous `requests.get` and `open().write` in the `process_url` endpoint with `httpx.AsyncClient` and `aiofiles.open`. This prevents the FastAPI event loop from blocking during large file downloads. Updated test suite in `tests/test_url_upload.py` to use `AsyncMock` to mock `httpx.AsyncClient.stream` contexts and async generators properly, covering all original conditions and HTTP error handling paths. Added dependencies `aiofiles` and `types-aiofiles` to resolve MyPy typing CI failures, and mitigated CodeQL security alerts regarding user-provided path extensions by deriving the extension from original_filename and filtering out all non-alphanumerics. Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>