Add Docker infrastructure for dev and prod environments

- Separate PHP Dockerfiles (dev/prod) with extensions and prod opcache/php.ini optimization
- docker-compose-dev: PHP, PostgreSQL, Redis, Messenger, Mailpit, RedisInsight
- docker-compose-prod: 2x PHP replicas, PgSQL master/slave with PgBouncer, 2x Messenger, Redis
- Makefile with build/start/stop/purge commands
- AGENT.md to restrict AI access to the repository

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Makefile

@@ -0,0 +1,27 @@
+.DEFAULT_GOAL := help
+
+## —— Help ————————————————————————————————————————
+help: ## Affiche la liste des commandes disponibles
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-20s\033[0m %s\n", $$1, $$2}'
+
+## —— Docker ——————————————————————————————————————
+build_dev: ## Build les images Docker pour le dev
+	docker compose -f docker-compose-dev.yml build
+
+build_prod: ## Build les images Docker pour la prod
+	docker compose -f docker-compose-prod.yml build
+
+start_dev: ## Lance les containers dev
+	docker compose -f docker-compose-dev.yml up
+
+start_prod: ## Lance les containers prod en background
+	docker compose -f docker-compose-prod.yml up -d
+
+stop_dev: ## Arrete les containers dev
+	docker compose -f docker-compose-dev.yml down
+
+purge_dev: ## Arrete et purge les containers dev (volumes inclus)
+	docker compose -f docker-compose-dev.yml down -v --rmi all --remove-orphans
+
+stop_prod: ## Arrete les containers prod
+	docker compose -f docker-compose-prod.yml down