- Add progress bar for restore and verify operations using progressbar/v3
- Replace in-memory blob cache with disk-based LRU cache (closes#29)
- Add helper wrappers for stdin/stdout/stderr IO
- Move FetchAndDecryptBlob into restore.go, remove blob_fetch_stub.go
- Use v.Stdout/v.Stdin instead of os.Stdout for all user-facing output
Rebased onto main, squashed to resolve conflicts.
