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>

backend/app/main.py

@@ -7,7 +7,7 @@ from typing import Any
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
-from app.api.routes import auth, canvas, edges, liveview, nodes, scan, status
+from app.api.routes import auth, canvas, edges, liveview, nodes, scan, status, zigbee
 from app.api.routes import settings as settings_routes
 from app.core.config import settings
 from app.core.scheduler import start_scheduler, stop_scheduler
@@ -55,6 +55,7 @@ app.include_router(scan.router, prefix="/api/v1/scan", tags=["scan"])
 app.include_router(status.router, prefix="/api/v1/status", tags=["status"])
 app.include_router(settings_routes.router, prefix="/api/v1/settings", tags=["settings"])
 app.include_router(liveview.router, prefix="/api/v1/liveview", tags=["liveview"])
+app.include_router(zigbee.router, prefix="/api/v1/zigbee", tags=["zigbee"])
 
 
 @app.get("/api/v1/health")