feat: add Z-Wave network scan via MQTT gateway

Import a Z-Wave JS UI (zwavejs2mqtt) network over the MQTT gateway API,
mirroring the existing Zigbee pipeline:

- New Z-Wave Import modal + sidebar entry (broker, prefix, gateway name)
- coordinator/router/end-device typing with mesh tree from node neighbors
- import to Pending section or straight to canvas
- Pending Devices gains a Z-Wave source filter
- shared mqtt_common helpers extracted from the zigbee service

ha-relevant: yes

frontend/src/utils/__tests__/zwaveProperties.test.ts

@@ -0,0 +1,38 @@
+import { describe, it, expect } from 'vitest'
+import { isZwaveType, buildZwaveProperties } from '../zwaveProperties'
+
+describe('isZwaveType', () => {
+  it('returns true for zwave types', () => {
+    expect(isZwaveType('zwave_coordinator')).toBe(true)
+    expect(isZwaveType('zwave_router')).toBe(true)
+    expect(isZwaveType('zwave_enddevice')).toBe(true)
+  })
+
+  it('returns false for non-zwave types', () => {
+    expect(isZwaveType('zigbee_router')).toBe(false)
+    expect(isZwaveType('server')).toBe(false)
+    expect(isZwaveType(undefined)).toBe(false)
+    expect(isZwaveType(null)).toBe(false)
+  })
+})
+
+describe('buildZwaveProperties', () => {
+  it('builds Z-Wave ID / Vendor / Model rows, all hidden', () => {
+    const props = buildZwaveProperties({ ieee_address: 'zwave-0xh-2', vendor: 'Aeotec', model: 'ZW100' })
+    expect(props).toEqual([
+      { key: 'Z-Wave ID', value: 'zwave-0xh-2', icon: null, visible: false },
+      { key: 'Vendor', value: 'Aeotec', icon: null, visible: false },
+      { key: 'Model', value: 'ZW100', icon: null, visible: false },
+    ])
+  })
+
+  it('omits empty fields', () => {
+    const props = buildZwaveProperties({ ieee_address: 'zwave-0xh-2', vendor: null, model: undefined })
+    expect(props.map((p) => p.key)).toEqual(['Z-Wave ID'])
+  })
+
+  it('never adds an LQI row', () => {
+    const props = buildZwaveProperties({ ieee_address: 'x', vendor: 'v', model: 'm' })
+    expect(props.some((p) => p.key === 'LQI')).toBe(false)
+  })
+})

frontend/src/utils/nodeIcons.ts

@@ -11,7 +11,7 @@ import {
   // Security & Auth
   Shield, ShieldCheck, Lock, Key, Users, UserCheck, Flame,
   // Automation & IoT
-  Zap, Workflow, Bot, Home, Thermometer, Lightbulb, Radio, BotMessageSquare, Webhook,
+  Zap, Workflow, Bot, Home, Thermometer, Lightbulb, Radio, RadioTower, Share2, BotMessageSquare, Webhook,
   // Smart Home / Sensors
   Plug, Power, BatteryCharging, Sun, DoorOpen, KeyRound, AlarmSmoke, Siren,
   Radar, PersonStanding, Vibrate, Droplet, Droplets, Wind, AirVent, Fan,
@@ -178,6 +178,9 @@ export const NODE_TYPE_DEFAULT_ICONS: Record<NodeType, LucideIcon> = {
   zigbee_coordinator: Radio,
   zigbee_router:      Zap,
   zigbee_enddevice:   Lightbulb,
+  zwave_coordinator:  RadioTower,
+  zwave_router:       Share2,
+  zwave_enddevice:    Lightbulb,
   generic:           Circle,
   group:             Circle,
   groupRect:         Circle,

frontend/src/utils/zwaveProperties.ts

@@ -0,0 +1,21 @@
+import type { NodeProperty, NodeType } from '@/types'
+
+const ZWAVE_TYPES: NodeType[] = ['zwave_coordinator', 'zwave_router', 'zwave_enddevice']
+
+export function isZwaveType(type: NodeType | string | undefined | null): boolean {
+  return !!type && (ZWAVE_TYPES as string[]).includes(type)
+}
+
+/** Build the Z-Wave ID/Vendor/Model property rows shown in the right panel.
+ * Matches backend `build_zwave_properties` (no LQI — Z-Wave has none). */
+export function buildZwaveProperties(input: {
+  ieee_address?: string | null
+  vendor?: string | null
+  model?: string | null
+}): NodeProperty[] {
+  const props: NodeProperty[] = []
+  if (input.ieee_address) props.push({ key: 'Z-Wave ID', value: input.ieee_address, icon: null, visible: false })
+  if (input.vendor) props.push({ key: 'Vendor', value: input.vendor, icon: null, visible: false })
+  if (input.model) props.push({ key: 'Model', value: input.model, icon: null, visible: false })
+  return props
+}