feat: standalone node-exporter + telegraf compose per node

Post-Swarm: node-exporter must run standalone with pid:host, since Swarm mode
blocked it and cross-node /proc namespaces contaminated swap metrics. Marks the
stacks/ definition superseded.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

compose/bart/node-exporter/docker-compose.yml

@@ -0,0 +1,24 @@
+services:
+  node-exporter:
+    image: prom/node-exporter:v1.7.0
+    container_name: node-exporter
+    hostname: bart
+    network_mode: host
+    pid: host
+    restart: unless-stopped
+    volumes:
+      - /proc:/host/proc:ro
+      - /sys:/host/sys:ro
+      - /:/rootfs:ro
+    command:
+      - '--path.procfs=/host/proc'
+      - '--path.rootfs=/rootfs'
+      - '--path.sysfs=/host/sys'
+      - '--collector.filesystem.mount-points-exclude=^/(sys|proc|dev|host|etc)($$|/)'
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "50m"
+        max-file: "3"
+    labels:
+      - "com.centurylinklabs.watchtower.enable=false"

compose/bart/telegraf/docker-compose.yml

@@ -0,0 +1,22 @@
+services:
+  telegraf:
+    image: telegraf:latest
+    container_name: telegraf
+    hostname: bart
+    restart: unless-stopped
+    environment:
+      - HOST_PROC=/host/proc
+      - HOST_SYS=/host/sys
+      - HOST_ETC=/host/etc
+    volumes:
+      - /mnt/docker-data/configs/telegraf/telegraf.conf:/etc/telegraf/telegraf.conf:ro
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+      - /sys:/host/sys:ro
+      - /proc:/host/proc:ro
+      - /etc:/host/etc:ro
+    mem_limit: 512M
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "50m"
+        max-file: "3"