fix: Move all stacks directly under stacks/ (no category subfolders)

stacks/monitoring/grafana/compose.yml

@@ -1,30 +0,0 @@
-services:
-  grafana:
-    image: grafana/grafana:latest
-    container_name: grafana
-    restart: unless-stopped
-    ports:
-      - "127.0.0.1:3000:3000"
-    volumes:
-      - grafana_data:/var/lib/grafana
-      - grafana_config:/etc/grafana
-    environment:
-      - GF_SECURITY_ADMIN_USER=${SECRET:grafana-admin-user}
-      - GF_SECURITY_ADMIN_PASSWORD=${SECRET:grafana-admin-pass}
-      - GF_USERS_ALLOW_SIGN_UP=false
-    networks:
-      - monitoring
-    healthcheck:
-      test: ["CMD-SHELL", "wget --spider -q http://localhost:3000/api/health || exit 1"]
-      interval: 30s
-      timeout: 10s
-      retries: 3
-      start_period: 30s
-
-volumes:
-  grafana_data:
-  grafana_config:
-
-networks:
-  monitoring:
-    driver: bridge