fix: use os.path.samefile for accurate directory comparison

Author: Zhe Yu

tests/test_cli_utils.py

@@ -613,7 +613,7 @@ async def test_find_project_root_at_root():
     with tempfile.TemporaryDirectory() as temp_dir:
         os.makedirs(os.path.join(temp_dir, ".git"))
         # in a git repo, find_project_root should not go beyond the git root
-        assert find_project_root(temp_dir, ".git") == temp_dir
+        assert os.path.samefile(find_project_root(temp_dir, ".git"), temp_dir)
         assert find_project_root(temp_dir, ".vectorcode") is None