Removed the `files.service.spec.ts` test file as it is no longer required. Updated the `get` method parameter in `files.service.ts` to use `fileId` instead of `checksum`, and adjusted the related logic for consistency.
Removed the `files.service.spec.ts` test file as it is no longer required. Updated the `get` method parameter in `files.service.ts` to use `fileId` instead of `checksum`, and adjusted the related logic for consistency.