fleet: register vm-esh-nas as 5th Docker host + canonical dockge stack

vm-esh-nas (10.0.50.154) is a NAS-adjacent Docker VM on the esh-pve-nas
hypervisor. Runs filezilla (port 5800), dockge, beszel-agent, dozzle-agent
with /mnt/{share,music,books,media} NFS-mounted from 10.0.50.50.
Use this host when a stack needs direct NFS mounts to the ESH NAS shares.

Canonicalize dockge as stacks/dockge/ — single compose used on all five
Docker hosts with per-host DOCKGE_HOST_LABEL/DOCKGE_HOST_IP in .env so
each card on the homepage points at its own instance. Labeled
homepage.group=Service Networking.

Beszel + Dozzle agent dirs also renamed to beszel-agent-<site> /
dozzle-agent-<site> pattern across the fleet for consistency.

stacks/dockge/compose.yaml

@@ -0,0 +1,37 @@
+# Dockge — per-host Docker Compose UI (https://dockge.kuma.pet/).
+#
+# One instance runs on every Docker host so the compose dir is manageable
+# from a browser. Each host sets DOCKGE_HOST_LABEL + DOCKGE_HOST_IP in its
+# .env so the homepage card points at the right place.
+#
+# All tunables live in .env — edit that, not this file.
+
+services:
+  dockge:
+    image: louislam/dockge:${DOCKGE_VERSION:-latest}
+    container_name: dockge
+    restart: unless-stopped
+    ports:
+      - "${DOCKGE_PORT:-5001}:5001"
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+      - dockge_data:/app/data
+      - /opt/docker:/opt/docker
+    environment:
+      - DOCKGE_STACKS_DIR=/opt/docker/compose
+    networks:
+      - tnet
+    labels:
+      - homepage.group=Service Networking
+      - homepage.name=Dockge (${DOCKGE_HOST_LABEL})
+      - homepage.icon=si-portainer
+      - homepage.description=Compose UI on ${DOCKGE_HOST_LABEL}
+      - homepage.href=http://${DOCKGE_HOST_IP}:${DOCKGE_PORT:-5001}
+
+volumes:
+  dockge_data:
+
+networks:
+  tnet:
+    name: traefik-net
+    external: true