feat(skel): docker-compose for local Postgres (integration-test stack)

docker-compose.yml

@@ -0,0 +1,26 @@
+version: "3.9"
+
+# Local development environment for Minstrel.
+# Not used by CI — integration tests run against this compose stack manually:
+#   docker compose up -d postgres
+#   go test ./...    # runs full tests (no -short flag)
+
+services:
+  postgres:
+    image: postgres:16-alpine
+    environment:
+      POSTGRES_USER: minstrel
+      POSTGRES_PASSWORD: minstrel
+      POSTGRES_DB: minstrel
+    ports:
+      - "5432:5432"
+    volumes:
+      - minstrel-pgdata:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U minstrel -d minstrel"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+
+volumes:
+  minstrel-pgdata: