HEAD method support, PHP 8.2, CI modernization

What's New

• HEAD method support — Routes::map() now accepts HEAD as a valid HTTP method (#50)
• PHP 8.2 required — minimum PHP version bumped from 7.3 to 8.2
• Mantle framework integration — added mantle-framework/support, contracts, and container as
  dependencies

Improvements

• Major refactor of Routes.php for readability, structure, and inline documentation
• Modernized string operations (str_contains, str_starts_with) for clarity and performance
• Clearer parameter descriptions on load()
• Template filter callback now receives the current template parameter

Tooling & CI

• Migrated from Travis CI to GitHub Actions (lint, Rector, PHPUnit)
• Added Easy Coding Standard (ecs.php) and Rector (rector.php) configs
• Updated PHPUnit config and test bootstrap
• Rewrote test suite under tests/RoutesTest.php with expanded coverage

Fixes

• Corrected "Preceeding" → "Preceding" in test names
• Reset matches_class_test array between class route assertions
• Assorted .gitattributes / .gitignore cleanup

Breaking Changes

• PHP 8.2 is now the minimum supported version. Projects on older PHP must stay on 0.9.2 or
  upgrade their runtime before installing this release.

Full Changelog: 0.9.2...0.10.0