feat: availability broadcast (Kind 30078) + WiFi auto-connect

Wire up the availability broadcast composable to publish the ATM's
status as a replaceable Kind 30078 Nostr event. Publishes on
availability change (debounced) and as a 5-minute heartbeat so
monitors can detect offline machines.

Also adds WiFi auto-connect for BATM3: reads SSID/PSK from
/var/lib/lamassu-atm/wifi.conf at boot. Credentials stay local.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/machine/src/composables/useAvailabilityBroadcast.ts

@@ -93,9 +93,22 @@ export function useAvailabilityBroadcast(options: UseAvailabilityBroadcastOption
     { deep: true }
   )
 
+  // Heartbeat: republish every 5 minutes so monitors know the machine is alive.
+  // If the latest Kind 30078 event is older than ~10 minutes, the machine is offline.
+  const heartbeatInterval = setInterval(
+    () => {
+      publish(computeAvailability())
+    },
+    5 * 60 * 1000
+  )
+
   // Publish immediately on setup
   const initial = computeAvailability()
   publish(initial)
 
-  return { computeAvailability }
+  function stop() {
+    clearInterval(heartbeatInterval)
+  }
+
+  return { computeAvailability, stop }
 }

apps/machine/src/stores/atm.ts

@@ -21,6 +21,7 @@ import {
   type ManagementResponse,
 } from '@lamassu/clink'
 import type { TransactionRecord } from '@/types/state'
+import { useAvailabilityBroadcast } from '@/composables/useAvailabilityBroadcast'
 
 // Check if we're running in Electron
 const isElectron = typeof window !== 'undefined' && window.electronAPI !== undefined
@@ -308,6 +309,10 @@ export const useAtmStore = defineStore('atm', () => {
     return snapshot.value?.context ?? null
   })
 
+  const inventory = computed((): Record<number, number> => {
+    return context.value?.inventory ?? {}
+  })
+
   const fiatSymbol = computed(() => {
     const symbols: Record<string, string> = { USD: '$', GTQ: 'Q', EUR: '€', GBP: '£', MXN: '$' }
     return symbols[fiatCode.value] || fiatCode.value
@@ -557,6 +562,9 @@ export const useAtmStore = defineStore('atm', () => {
 
       // Initialize state machine with real services
       initialize(servicesWithInventory)
+
+      // Start broadcasting availability (Kind 30078) with 5-minute heartbeat
+      startAvailabilityBroadcast(services.nostrClient, services.identity, 'atm')
     } catch (error) {
       console.error('[ATM] Failed to connect to Lightning.Pub:', error)
       connectionStatus.value = 'error'
@@ -847,6 +855,9 @@ export const useAtmStore = defineStore('atm', () => {
         }
       })
 
+      // Start broadcasting availability (Kind 30078)
+      startAvailabilityBroadcast(lightning.nostrClient, lightning.identity, 'atm')
+
       console.log('[ATM] Fully initialized with HAL + Lightning')
     } catch (error) {
       console.error('[ATM] HAL initialization failed:', error)
@@ -1099,6 +1110,9 @@ export const useAtmStore = defineStore('atm', () => {
 
       // Real hardware connected — disable mock bill simulator
       debugMode.value = false
+      // Start broadcasting availability (Kind 30078)
+      startAvailabilityBroadcast(lightning.nostrClient, lightning.identity, 'atm')
+
       console.log('[ATM] Fully initialized with HAL (IPC) + Lightning')
     } catch (error) {
       console.error('[ATM] HAL initialization failed:', error)
@@ -1225,6 +1239,23 @@ export const useAtmStore = defineStore('atm', () => {
     }
   }
 
+  /** Start broadcasting ATM availability (Kind 30078) with 5-minute heartbeat */
+  let stopAvailabilityBroadcast: (() => void) | null = null
+
+  function startAvailabilityBroadcast(nostrClient: any, identity: any, model: string) {
+    if (stopAvailabilityBroadcast) return
+
+    const { stop } = useAvailabilityBroadcast({
+      nostrClient,
+      identity,
+      inventory,
+      balanceSats,
+      fiatCode: fiatCode.value,
+      model,
+    })
+    stopAvailabilityBroadcast = stop
+  }
+
   return {
     // State
     actor,

deploy/nixos/hardware/batm3.nix

@@ -68,6 +68,43 @@
     hybrid-sleep.enable = false;
   };
 
+  # WiFi: read credentials from /var/lib/lamassu-atm/wifi.conf (not in repo)
+  # Format: SSID=MyNetwork\nPSK=MyPassword
+  system.activationScripts.wifi-setup = ''
+        WIFI_CONF="/var/lib/lamassu-atm/wifi.conf"
+        if [ -f "$WIFI_CONF" ]; then
+          SSID=$(grep '^SSID=' "$WIFI_CONF" | cut -d= -f2-)
+          PSK=$(grep '^PSK=' "$WIFI_CONF" | cut -d= -f2-)
+          if [ -n "$SSID" ] && [ -n "$PSK" ]; then
+            CONN_FILE="/etc/NetworkManager/system-connections/$SSID.nmconnection"
+            if [ ! -f "$CONN_FILE" ]; then
+              cat > "$CONN_FILE" << EOF
+    [connection]
+    id=$SSID
+    type=wifi
+    autoconnect=true
+
+    [wifi]
+    mode=infrastructure
+    ssid=$SSID
+
+    [wifi-security]
+    key-mgmt=wpa-psk
+    psk=$PSK
+
+    [ipv4]
+    method=auto
+
+    [ipv6]
+    method=auto
+    EOF
+              chmod 600 "$CONN_FILE"
+              echo "[WiFi] Created connection for $SSID"
+            fi
+          fi
+        fi
+  '';
+
   # eGalax touchscreen (Dell 9030 AIO built-in panel)
   # The eGalax HID descriptor confuses libinput (treats it as touchpad).
   # Fix: unbind from usbhid at boot, bind to usbtouchscreen kernel module,