Add infra/ — full stack config as deployed on RPi 3B+

Captures everything needed to rebuild the stack from scratch:

infra/compose.yaml
- mosquitto (eclipse-mosquitto:latest)
- zigbee2mqtt (ghcr.io/pine64/zigbee2mqtt:latest-dev, BLZ fork)
- nodered (nodered/node-red:latest)

infra/mosquitto/config/mosquitto.conf
- anonymous listener on 1883, file logging, persistence on

infra/zigbee2mqtt/
- configuration.yaml: 5 paired devices with friendly names, 1 group
- coordinator_backup.json: zigbee network key + pan id (recovery)
- state.json: per-device persisted state (ON/OFF, linkquality)

infra/nodered/
- settings.js: nodered defaults (flowFile: flows.json, no auth)
- start.sh: patches Dashboard 2.0 SPA with <base href> at startup

Also:
- Updated z2m groups section to rename Laser & Fog -> DJ Booth
  (matches the friendly_name already in devices section)
- Pushed the same change to live /root/zigbee2mqtt/configuration.yaml
  and restarted the zigbee2mqtt container
- .gitignore: output/ (regenerated on every build, churns uuid ids)
- README.md: link to infra/README.md for rebuild procedure

infra/compose.yaml

@@ -0,0 +1,55 @@
+services:
+  mosquitto:
+    image: eclipse-mosquitto:latest
+    container_name: mosquitto
+    restart: unless-stopped
+    user: "1883:1883"
+    ports:
+      - "1883:1883"
+    volumes:
+      - ./mosquitto/config:/mosquitto/config
+      - ./mosquitto/data:/mosquitto/data
+      - ./mosquitto/log:/mosquitto/log
+
+  zigbee2mqtt:
+    image: ghcr.io/pine64/zigbee2mqtt:latest-dev   # BLZ fork, NOT koenkk
+    container_name: zigbee2mqtt
+    restart: unless-stopped
+    depends_on:
+      - mosquitto
+    ports:
+      - "8080:8080"
+    volumes:
+      - ./zigbee2mqtt:/app/data
+    devices:
+      - /dev/ttyUSB0:/dev/ttyUSB0
+    environment:
+      TZ: America/Los_Angeles
+
+  # govee2mqtt:
+  #   image: ghcr.io/wez/govee2mqtt:latest
+  #   container_name: govee2mqtt
+  #   restart: unless-stopped
+  #   network_mode: host
+  #   environment:
+  #     GOVEE_EMAIL: your@email.com
+  #     GOVEE_PASSWORD: yourpassword
+  #     GOVEE_API_KEY: your-api-key
+  #     MQTT_HOST: 127.0.0.1
+  #     TZ: America/Los_Angeles
+  #
+  nodered:
+    image: nodered/node-red:latest
+    container_name: nodered
+    restart: unless-stopped
+    depends_on:
+      - mosquitto
+    user: "1000:1000"
+    ports:
+      - "1880:1880"
+    volumes:
+      - ./nodered:/data
+    environment:
+      TZ: America/Los_Angeles
+      DASHBOARD_BASE_HREF: /dashboard/
+    command: ["sh", "/data/start.sh"]