Upgrade to Laravel Zero 13.x, Pest 4 and PHP 8.5 support

[dmason30]

Summary

Upgrades the app to Laravel 13 / Laravel Zero 13.x, Pest v4, and adds PHP 8.5 to the CI matrix.

Important

Draft until Laravel Zero tags a stable 13.x release. Laravel Zero currently only has a dev-feature/13.x-upgrade branch (no stable tag), so laravel-zero/framework and laravel-zero/foundation are pinned to dev-feature/13.x-upgrade as 13.0.0. Once v13 is tagged, swap both constraints to ^13.0 and re-run composer update before marking ready for review.

Changes

• illuminate/encryption ^12.0 → ^13.0 (13.20.0)
• laravel-zero/framework / laravel-zero/foundation → dev-feature/13.x-upgrade as 13.0.0 (see note above)
• pestphp/pest ^3.8 → ^4.0 (4.7.5), migrated phpunit.xml.dist off the deprecated schema
• PHP requirement ^8.2 → ^8.3 (required by both Laravel 13 and Pest 4)
• CI test matrix: added 8.5, dropped 8.2 → [8.5, 8.4, 8.3]
• Bumped laravel/pint to ^1.25 and nunomaduro/termwind to ^2.4, applied new Pint fixes
• Rebuilt builds/padlock phar as 5.0.0 (major bump due to the PHP floor change)

Workaround

The Laravel Zero 13.x branch's test lifecycle unconditionally calls FormRequest::flushState(), but FormRequest depends on illuminate/http and illuminate/validation, which Laravel Zero strips out. Both are added as dev-only dependencies (not bundled in the phar). They can likely be removed once this is fixed upstream or the stable release lands.

Test plan

• ./vendor/bin/pest passes on PHP 8.5
• Verified env:encrypt → env:decrypt round-trip via both php padlock and the rebuilt phar
• Rebuilt phar reports Padlock 5.0.0 and runs without deprecation warnings on PHP 8.5