[Feature]: Zip contents checking

[Malcolmnixon]

Problem Statement

It would be nice to use FileAssert to check that Zip files (including nupkgs and jars) contain expected files - and possibly contents.

Proposed Solution

Add zip file checking rules. For now we can just check that contents exist - don't worry about allowing text/html/json/yaml/pdf/zip checking of contents as that would probably require those rules to have an abstract filesystem interface that can point to a real drive or zip contents.

Alternatives Considered

No response

Usage Examples

Benefits

Could be used to verify release packages contain expected content.

Priority

Low - Nice to have

Willingness to Contribute

Yes, I can submit a pull request

Additional Context

No response

Checklist

• I have searched existing issues to ensure this is not a duplicate
• I have provided a clear description of the feature
• I have explained why this feature would be useful