feat: Add zip-contains rule for asserting zip archive entry existence

[Copilot]

Pull Request

Description

Adds a zip-contains assertion rule enabling FileAssert to validate that zip archives (including .nupkg, .jar, etc.) contain expected entries, with optional min/max count constraints and glob pattern matching.

New rule: zip-contains

rules:
  - type: zip-contains
    entries:
      - pattern: 'lib/net8.0/MyLib.dll'
        min: 1
        max: 1
      - pattern: 'lib/**/*.dll'
        min: 1

Entry paths are normalized to forward slashes before matching; glob patterns are resolved via Microsoft.Extensions.FileSystemGlobbing (same mechanism as FileAssertFile). No new NuGet dependencies — uses System.IO.Compression from the BCL.

Changes

• Modeling/FileAssertZipAssert.cs — new rule implementation; opens zip via ZipFile.OpenRead, collects all entry names, applies Matcher per pattern, enforces min/max
• Configuration/FileAssertData.cs — new FileAssertZipEntryData and FileAssertZipData DTOs
• Modeling/FileAssertRule.cs — registers "zip-contains" type
• README.md — documents new rule with YAML examples
• Documentation — design, requirements (reqstream), and verification docs added under docs/; introduction.md and .reviewmark.yaml updated to include the new unit

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code quality improvement

Related Issues

Closes #

Pre-Submission Checklist

Before submitting this pull request, ensure you have completed the following:

Build and Test

• Code builds successfully and all tests pass: pwsh ./build.ps1
• Code produces zero warnings

Code Quality

• New code has appropriate XML documentation comments
• Static analyzer warnings have been addressed

Quality Checks

• All linters pass: pwsh ./lint.ps1

Testing

• Added unit tests for new functionality
• Updated existing tests if behavior changed
• All tests follow the AAA (Arrange, Act, Assert) pattern
• Test coverage is maintained or improved

Documentation

• Updated README.md (if applicable)
• Updated docs/ documentation (if applicable)
• Added code examples for new features (if applicable)
• Updated requirements.yaml (if applicable)

Additional Notes

zip-contains intentionally checks only entry existence. Recursive content inspection of zip entries (text/HTML/JSON/etc.) is explicitly deferred — it would require abstracting the file-system interface used by existing rules.