Restore CamelCaseTrait for 1.x backward compatibility

[koriym]

Problem

ray/media-query 1.1.0 no longer ships Ray\MediaQuery\CamelCaseTrait. This is a source-compatible break for existing entity/read-model classes that still import the trait:

use Ray\MediaQuery\CamelCaseTrait;

final class AdminEntity
{
    use CamelCaseTrait;
}

After upgrading to 1.1.0, those classes fail at load time with Trait "Ray\MediaQuery\CamelCaseTrait" not found.

Evidence

Installed package:

$ composer show ray/media-query --format=json
versions: 1.1.0
source reference: 507d1efffd99f883b1c1afbc9d0cf1a35f927129

The 1.1.0 package contains Ray\MediaQuery\StringCase, but not src/CamelCaseTrait.php. The bundled changelog explicitly says:

CamelCaseTrait has been removed

MIGRATION.md says the trait has been deprecated, but the symbol is not present, so consumers get a hard fatal instead of a deprecation path.

Expected

For the 1.x line, please keep Ray\MediaQuery\CamelCaseTrait available for backward compatibility, ideally marked deprecated and implemented with the previous behavior or as a compatibility wrapper.

The 0.17.1 implementation was small enough to keep as a deprecated BC layer:

trait CamelCaseTrait
{
    public function __set(string $name, mixed $value): void
    {
        $propName = lcfirst(str_replace('_', '', ucwords($name, '_')));
        $this->{$propName} = $value;
    }
}

Why this matters

The recommended replacement (StringCase plus constructor property promotion) is a reasonable modernization path, but removing the trait in 1.x makes a minor upgrade require immediate source edits across all hydrated entity classes. Keeping the symbol avoids unnecessary upgrade friction while still allowing documentation to recommend migration away from it.