fix: use named volume for prometheus config, seed in CD workflow

docker-compose.prod.yml

@@ -102,7 +102,7 @@ services:
     container_name: linearvoid-prometheus
     restart: unless-stopped
     volumes:
-      - ./monitoring/prometheus/prometheus.yml:/etc/prometheus/prometheus.yml
+      - prometheus-config:/etc/prometheus
       - prometheus-data:/prometheus
     ports:
       - "9090:9090"
@@ -142,4 +142,5 @@ volumes:
   redis-data:
   postgres-data:
   prometheus-data:
+  prometheus-config:
   grafana-data: