feat: add Laravel middleware composer package

[emptyteabot]

Summary

• Add a Laravel Composer package template under templates/laravel-middleware.
• Include aport.policy route middleware, an APort HTTP client, config publishing, and an aport:policy Artisan command.
• Add a minimal Laravel refund route/controller example plus Testbench/PHPUnit coverage for allow, deny, missing agent id, client error, and fail-open paths.
• Normalize APort denial reasons, preserve agent/policy request attributes on fail-open, and guard custom context merging against invalid attribute values.
• Update the root README to list the Laravel template as active.

Verification

• composer install --no-interaction --prefer-dist
• php vendor/bin/phpunit - 9 tests, 19 assertions passing
• composer validate --strict
• php -l across all package PHP files
• git diff --check

Closes #15

Payout address: 0xe2e86bdb8753c24032f2ad42b4c1bd9748385a7d

[emptyteabot]

Fresh local verification completed for the Laravel middleware package.

Commands run from templates/laravel-middleware:

• composer install --no-interaction --no-progress --prefer-dist
• composer test -> 9 tests passed, 19 assertions

No live APort API key or external API call was required; tests use Laravel HTTP fakes.

[emptyteabot]

Gentle follow-up: this PR is still mergeable and the Laravel middleware package verification passes locally (composer test -> 9 tests, 19 assertions). Happy to adjust anything needed for review.