infra: expose timescale_db port 5888 for direct pgcli access

Maps host port 5888 → container port 5432 so the DB can be reached
directly from the MacBook (requires UFW allow 5888/tcp on the server).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docker-compose.yaml

@@ -6,6 +6,8 @@ services:
       - POSTGRES_DB=${POSTGRES_DB}
       - POSTGRES_USER=${POSTGRES_USER}
       - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
+    ports:
+      - "5888:5432"
     volumes:
       - timescale-data:/var/lib/postgresql/data
     healthcheck: