feat(builtins): add zip/unzip commands

[chaliy]

Summary

zip and unzip handle the most common archive format on the web. While tar/gzip are implemented, zip is the default format for GitHub releases, downloaded artifacts, and cross-platform file exchange.

Requested Flags

zip

Flag	Description
(default)	Create zip archive
-r	Recurse into directories
-j	Junk (strip) directory paths
-u	Update existing archive (add changed files)
-d	Delete entries from archive
-x pattern	Exclude files matching pattern
-9 / -0	Compression level (best / store only)

unzip

Flag	Description
(default)	Extract all files
-l	List archive contents
-d dir	Extract to directory
-o	Overwrite without prompting
-j	Junk paths (extract flat)
-p	Extract to stdout (pipe)
file.zip pattern	Extract only matching files

Use Cases

# Create archive
zip -r project.zip src/ lib/ README.md

# Extract
unzip artifact.zip -d output/

# List contents
unzip -l release.zip

# Extract specific file
unzip data.zip "*.csv" -d data/

# Pipe content
unzip -p archive.zip config.json | jq .version

Implementation Notes

• Use zip crate from crates.io for format handling
• Must operate on VFS (read/write virtual files)
• Validate paths in zip entries to prevent directory traversal (same as tar)
• Compression level support is nice-to-have; deflate default is sufficient
• Enforce VFS size limits when extracting

[chaliy]

Resolved in PR #585 or #588