CUB-231: Mosquitto MQTT broker setup on Pi Zero 2 W hub

- Install script for Mosquitto MQTT broker on Pi Zero 2 W (10.60.1.101)
- Persistence enabled with data stored in /var/lib/mosquitto/data/
- Topic ACL configuration for hub, sensor, mobile, and admin users
- systemd service with security hardening (NoNewPrivileges, ProtectSystem)
- Configuration files: mosquitto.conf, acl.conf
- Validation script to verify setup before deployment

mosquitto.conf

@@ -0,0 +1,26 @@
+# Main Mosquitto Configuration
+# Target: Pi Zero 2 W Hub (10.60.1.101)
+
+# Persistence
+persistence true
+persistence_location /var/lib/mosquitto/data/
+persistence_file mosquitto.db
+
+# Listener
+listener 1883
+
+# Authentication
+allow_anonymous false
+
+# ACL
+acl_file /etc/mosquitto/acl/acl.conf
+
+# Logging
+log_dest file /var/log/mosquitto/mosquitto.log
+log_type all
+
+# Max connections
+max_connections 100
+
+# Keep alive
+persistent_client_expiration 4w