feat: power-loss boot resilience for Klubhaus DietPi

- restart: always for stack services
- harden-boot.sh: fsck.repair, panic reboot, hardware watchdog,
  docker+zerotier enabled, klubhaus-stack.service autostart
- kuma-online.sh: push up-heartbeat to Kuma on boot
- RESILIENCE.md documents the Aug 30 failure + apply steps

compose.yaml

@@ -2,7 +2,7 @@ services:
   mosquitto:
     image: eclipse-mosquitto:latest
     container_name: mosquitto
-    restart: unless-stopped
+    restart: always
     user: "1883:1883"
     ports:
       - "1883:1883"
@@ -14,7 +14,7 @@ services:
   zigbee2mqtt:
     image: ghcr.io/pine64/zigbee2mqtt:latest-dev   # BLZ fork, NOT koenkk
     container_name: zigbee2mqtt
-    restart: unless-stopped
+    restart: always
     depends_on:
       - mosquitto
     ports:
@@ -41,7 +41,7 @@ services:
   nodered:
     image: nodered/node-red:latest
     container_name: nodered
-    restart: unless-stopped
+    restart: always
     depends_on:
       - mosquitto
     user: "1000:1000"