Upgrade Composer constraints for Laravel 13 compatibility - #1400

This update moves the application onto the Laravel 13 dependency line and refreshes the related Packagist constraints needed to keep the current stack resolvable. It also aligns the AI SDK and supporting packages with the newer framework/runtime requirements.

• Framework baseline

  • Bump laravel/framework to ^13.0
  • Raise the PHP requirement to ^8.4 to match Laravel 13 / package constraints

• AI SDK

  • Update laravel/ai from a pinned 0.2.x constraint to the current compatible 0.7.x line

• Dependency compatibility

  • Move laravel/tinker to ^3.0
  • Add a Laravel 13-compatible spatie/laravel-model-states branch alias for packages that still depend on ^2.x

Example:

"require": {
  "php": "^8.4",
  "laravel/ai": "^0.7.2",
  "laravel/framework": "^13.0",
  "laravel/tinker": "^3.0",
  "spatie/laravel-model-states": "dev-l13-support as 2.14.1"
}