feat(infra): compose profiles, Makefile, local override example

All services sit behind profiles (db, gateway, obsidian) selected via
COMPOSE_PROFILES in .env; Makefile with the usual verbs and a `deploy`
target that pushes main:stable.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Makefile

@@ -0,0 +1,33 @@
+.PHONY: up recreate down restart rebuild gateway logs shell deploy
+
+up:
+	docker compose up -d
+
+recreate:
+	docker compose up -d --force-recreate
+
+down:
+	docker compose down
+
+restart:
+	$(MAKE) recreate
+
+rebuild:
+	docker compose build
+	docker compose up -d
+
+gateway:
+	docker compose build gateway
+	docker compose up -d gateway
+
+logs:
+	docker compose logs -f $(filter-out $@,$(MAKECMDGOALS))
+
+shell:
+	docker exec -it beaver-gateway bash
+
+deploy:
+	git push origin main:stable
+
+%:
+	@: