Initial: Node-RED flow validator with conftest/Rego

- Declarative YAML flow format
- Python flow2json converter with auto-positioning
- Rego policies: 14 validation rules for flow integrity
- Conftest integration
- justfile workflow: generate → validate → deploy

flows/zigbee-monitor.yaml

@@ -0,0 +1,48 @@
+version: 1
+
+brokers:
+  mosquitto:
+    host: mosquitto
+    port: 1883
+
+dashboards:
+  - tab: Home
+    icon: dashboard
+    groups:
+      - name: Zigbee
+        width: 6
+
+flows:
+  - tab: Zigbee Monitor
+    description: Monitor and control zigbee2mqtt coordinator
+    nodes:
+      - id: zigbee-in
+        type: mqtt-in
+        broker: mosquitto
+        topic: zigbee2mqtt/#
+        qos: 2
+
+      - id: debug
+        type: debug
+
+      - id: last-msg
+        type: ui-text
+        group: Zigbee
+        format: "{{msg.payload|json}}"
+
+      - id: permit-btn
+        type: ui-button
+        group: Zigbee
+        label: "Permit Join (60s)"
+        topic: zigbee2mqtt/bridge/request/permit_join
+        payload:
+          value: true
+          time: 60
+
+      - id: mqtt-out
+        type: mqtt-out
+        broker: mosquitto
+
+    wires:
+      zigbee-in: [debug, last-msg]
+      permit-btn: [mqtt-out]