Large logical size (Docker.raw) causes misleading disk usage — consider using allocated size

[StudentWeis]

Env:

• OS: macOS 15.5 (ARM64)
• space version: 1.1.3

What Happen:
A file at ~/Library/Containers/com.docker.docker/Data/vms/0/data/Docker.raw appears in the report as "1.0 TB". This large logical size causes sorting and summary results to be misleading.

Root cause:
The code currently uses metadata.len() / logical size semantics (or equivalent). For sparse or VM image files, this reports the file’s logical size rather than actual allocated blocks.

Suggested fix:
On Unix/macOS, use allocated blocks for disk usage: metadata.blocks() * 512 (std::os::unix::fs::MetadataExt) to compute actual allocated bytes.
Expose a CLI option to choose between "logical size" and "allocated size", or document the current behavior and add a blacklist for known VM image paths (e.g. com.docker.docker).

My attempts:

[StudentWeis]

@emilevr I don't know if I got that right.