feat: add ignorePaths method to exclude specified paths from arch ana…

[sonalidudhia]

Summary

This PR introduces a minimal ignorePaths() API for architecture expectations to reduce noise during architecture analysis.

In larger projects, architecture rules may unintentionally analyze generated, infrastructure, or third-party files (for example migrations, vendor code, cache, or generated artifacts), which can create false positives unrelated to application boundaries.

Example:

arch()
    ->expect('App')
    ->ignorePaths([
        'vendor',
        'database/migrations',
    ])
    ->not->toUse(['dd', 'dump']);

Why

Architecture tests are typically intended to validate application boundaries and conventions.

In practice, projects often contain directories that are:

• generated
• infrastructure-related
• historical (e.g. migrations)
• third-party

These may not be desirable targets for architecture expectations and can introduce noise into otherwise intentional rules.

This PR adds a small, framework-agnostic API to selectively exclude paths from architecture analysis.

Design

The implementation intentionally keeps the API minimal:

• single fluent API: ignorePaths(array $paths)
• framework agnostic
• chainable with existing expectations
• cross-platform path normalization
• no additional configuration
• no framework-specific helpers

Tests

Added coverage for:

• single ignored path
• multiple ignored paths
• nested directory matching
• partial path matching
• Windows path separators
• non-ignored files remaining analysable
• chaining with existing expectations