Update deployment pipeline, Makefile and README

- Makefile: add install_dev, install_prod, migrations, clear_prod, maintenance commands
- Playbook: full deploy flow (maintenance, stop, install, start, migrate, clear, caddy, messenger)
- Supervisor config for 2 messenger instances
- Workflow: SSH key setup with server IP
- hosts.ini: use IP instead of domain, sudo without password
- README: full documentation

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

Makefile

@@ -32,7 +32,7 @@ install_dev: ## Install les dependances dev via Docker
 	docker compose -f docker-compose-dev.yml exec bun bun install
 
 install_prod: ## Install les dependances et build les assets pour la prod
-	composer install --no-dev --optimize-autoloader
+	docker compose -f docker-compose-prod.yml exec php composer install --no-dev --optimize-autoloader
 	bun install
 	bun run build
 
@@ -45,3 +45,15 @@ migrate_dev: ## Execute les migrations via Docker dev
 
 migrate_prod: ## Execute les migrations en prod via Docker
 	docker compose -f docker-compose-prod.yml exec php php bin/console doctrine:migrations:migrate --no-interaction --env=prod
+
+## —— Cache ————————————————————————————————————————
+clear_prod: ## Clear le cache Symfony et le pool opcache en prod via Docker
+	docker compose -f docker-compose-prod.yml exec php php bin/console cache:clear --env=prod
+	docker compose -f docker-compose-prod.yml exec php php bin/console cache:pool:clear --all --env=prod
+
+## —— Maintenance ——————————————————————————————————
+maintenance_on: ## Active le mode maintenance
+	touch public/.update
+
+maintenance_off: ## Desactive le mode maintenance
+	rm -f public/.update