v0.3.0: Guzzle 8 and a Laravel Boost skill

Added

• A Laravel Boost guideline and the hindsight-php-agent-memory agent skill. php artisan boost:install offers them under third-party packages (checked with Boost 2.10.4).

Fixed

• The package can be installed in a new Laravel 13 application: it allows Guzzle 8, which Laravel 13.40 installs by default. Before, Composer refused fedoseev/hindsight-php there unless Guzzle was downgraded. CI now runs on Guzzle 8 and keeps a Guzzle 7 job.