Need checksum to check the integrity of the File Data

When data is passed from the client to the server and between servers, data may be lost, resulting in incomplete data. A checksum is required to ensure the integrity of the data

Start by tracing the Rust client-to-server and server-to-server file-data paths in the sealfs repository. Determine where checksum generation and verification belong, what incomplete-data behavior is required, and how integrity checks should be tested; the issue is complete when transfers detect altered or incomplete file data.

Written by the indexing model from the issue text.