feat: add Zigbee2MQTT network map importer

- Backend: async MQTT service (aiomqtt) to fetch Z2M networkmap via bridge API
- Backend: FastAPI router at /api/v1/zigbee with /import and /test-connection
- Backend: Pydantic v2 schemas for request/response validation
- Backend: coordinator → router → end-device parent_id hierarchy builder
- Frontend: ZigbeeImportModal with MQTT config form, Test Connection, Fetch Devices
- Frontend: device list grouped by type (coordinator/router/enddevice) with checkboxes
- Frontend: ZigbeeCoordinatorNode, ZigbeeRouterNode, ZigbeeEndDeviceNode canvas nodes
- Frontend: Zigbee Import button in sidebar alongside Scan Network
- Frontend: handleZigbeeAddToCanvas wires selected devices + edges onto canvas
- Tests: full unit test suite for parser, hierarchy builder, MQTT mocks
- Tests: API endpoint tests for /zigbee/import and /zigbee/test-connection
- Tests: Vitest component tests for ZigbeeImportModal
- Docs: docs/zigbee-import.md with full usage, MQTT config, troubleshooting guide
- Docs: README.md Zigbee2MQTT Import section

Co-authored-by: CyberKeys <noreply@openclaw.ai>

frontend/src/api/client.ts

@@ -72,3 +72,26 @@ export const settingsApi = {
   get: () => api.get<{ interval_seconds: number }>('/settings'),
   save: (data: { interval_seconds: number }) => api.post<{ interval_seconds: number }>('/settings', data),
 }
+
+export const zigbeeApi = {
+  testConnection: (data: {
+    mqtt_host: string
+    mqtt_port: number
+    mqtt_username?: string
+    mqtt_password?: string
+  }) =>
+    api.post<{ connected: boolean; message: string }>('/zigbee/test-connection', data),
+
+  importNetwork: (data: {
+    mqtt_host: string
+    mqtt_port: number
+    mqtt_username?: string
+    mqtt_password?: string
+    base_topic?: string
+  }) =>
+    api.post<{
+      nodes: import('@/components/zigbee/types').ZigbeeNode[]
+      edges: import('@/components/zigbee/types').ZigbeeEdge[]
+      device_count: number
+    }>('/zigbee/import', data),
+}