S0: Development Infrastructure

[derpixler]

As a developer
I want a ready-to-use development environment with automated quality checks
So that every story has a baseline to run tests and validate code style

Acceptance Criteria

Tooling

• composer.json — PHP >=8.3, PSR-only deps (http-client, http-factory, log), dev deps (phpunit, mockery, phpstan, phpcs, guzzle, league/openapi-psr7-validator)
• phpunit.xml.dist — unit + integration suites, integration/testcontainers groups excluded by default
• phpstan.neon.dist — level max, src/ paths
• test/bootstrap.php — autoload discovery

CI Pipeline

• .github/workflows/tests.yml — 2 jobs: unit (push/PR, phpstan + phpunit), testcontainers (workflow_dispatch, docker:dind)
• vendor/bin/phpcs --standard=PSR12 src/ — configured, 0 errors
• vendor/bin/phpstan analyse src/ --level=max — 0 real errors
• vendor/bin/phpunit --testsuite=unit — exits 0

Quality Gates

• All files have declare(strict_types=1)
• No ?> closing tags
• PSR-12 clean on all v3 files