chore: add Makefile to auto-create saas_network before docker compose up

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

deployments/Makefile

@@ -0,0 +1,15 @@
+NETWORK = saas_network
+
+.PHONY: network up down logs
+
+network:
+	docker network inspect $(NETWORK) >/dev/null 2>&1 || docker network create $(NETWORK)
+
+up: network
+	docker compose up --build -d
+
+down:
+	docker compose down
+
+logs:
+	docker compose logs -f