sdlc-symfony-conventions

Consolidated Symfony conventions (Symfony 6.4 / 7.x): attribute routing, controllers as services, autowiring/DI, Form types, Validation constraints, Voters for authorization, the Serializer/DTO contract, and Messenger. Apply when writing or reviewing Symfony backend code. Activated automatically by symfony-plugin/stack.md as a convention skill for the development phase. Apply when: writing or reviewing Symfony controllers, services, forms, validators, voters, and serialization. Do NOT use this skill for: - PHP language idioms (strict_types, enums, readonly) — see sdlc-php-conventions. - Doctrine queries / entities — see sdlc-doctrine-patterns. - Testing — injected by the QA phase (WebTestCase/KernelTestCase) + sdlc-php-testing.