- Updated `README.md` to clarify the distinction between public scratch IDs and internal blob IDs.
- Modified `filesystem.go` to introduce a new `BlobID` field in the `Metadata` struct, ensuring the separation of public and internal identifiers.
- Implemented functions to generate and reserve unique public IDs for scratch entries, improving metadata integrity.
- Adjusted tests in `filesystem_test.go` to validate the new ID structure and ensure public IDs do not match blob hashes.