.env, .env.dev, .env.prod, .env.test, and docker/.env contained real
production secrets and were tracked in git despite the Symfony
convention of keeping them local-only. Untrack them and ignore them
going forward; docker/.env.dist stays as a template but now uses
placeholder values instead of live credentials.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>