Update the remaining dependencies to their latest versions #623

Summary

Bring the remaining Composer dependencies to their latest versions, one package per change.

Why

composer outdated --direct lists three packages whose latest major version is outside the current constraint, and a few minor updates that the installed copies have not picked up.

Scope

One checkpoint per package, each one commit:

• gumlet/php-image-resize ^2.0 to 3.x (latest 3.0.1, requires PHP >=8.1). Used in src/Storage/UploadedFile.php; the DemoWeb and DemoApi PostService.php.tpl templates import ImageResizeException.
• povils/figlet ^0.1.0 to 1.x. Used in src/Console/Commands/VersionCommand.php.
• psr/simple-cache ^1.0 to 3.x. This is the breaking change: the interface gains parameter and return types, so Quantum\Cache\Cache and the Redis, Memcached, File and Database adapters need matching signatures, and an application with its own cache adapter has to update it.
• Minor and patch updates inside the existing constraints: vlucas/phpdotenv 5.8.0, and the dev tools phpstan/phpstan 2.3.2 and rector/rector 2.8.1, with any new findings fixed.

Where the code works on both the old and the new major version, widen the constraint (^2.0 || ^3.0) instead of replacing it, as was done for psr/log (#599).

Acceptance Criteria

• each package above is updated or has a stated reason for staying
• tests cover the changed behavior of each package
• CHANGELOG.md records each change, and says what an application must do for the breaking psr/simple-cache change
• the suite, PHPStan, code style and Rector checks pass