chore(release): 0.2.2 — keep all Symfony components on 7.4

- Add symfony/flex so extra.symfony.require "7.4.*" is enforced for
  transitive components (dependency-injection had drifted to 8.0.15)
- Group Symfony packages in Renovate and restrict them to ~7.4
- Copy symfony.lock in Docker builds so Flex doesn't re-apply recipes
- Add missing 0.2.1 changelog section and cut 0.2.2

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Dockerfile.dev

@@ -22,7 +22,7 @@ WORKDIR /app
 COPY docker/php/xdebug.ini /usr/local/etc/php/conf.d/docker-xdebug.ini
 COPY docker/php/conf.d/20-app.dev.ini $PHP_INI_DIR/app.conf.d/
 COPY docker/frankenphp/Caddyfile.dev /etc/caddy/Caddyfile
-COPY composer.json composer.lock* ./
+COPY composer.json composer.lock* symfony.lock ./
 RUN composer install --no-scripts --no-interaction --prefer-dist
 
 EXPOSE 8080