feat(ui): show Lightning.Pub nprofile QR on wallets support page

ShockWallet users can scan the nprofile to connect to the ATM's
Lightning.Pub instance. QR is built from VITE_LIGHTNING_PUB_PUBKEY
and VITE_RELAY_URL env vars with a graceful fallback.

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

apps/machine/src/views/SupportView.vue

@@ -1,6 +1,7 @@
 <script setup lang="ts">
 import { ref, computed, onMounted } from 'vue'
 import { useRouter } from 'vue-router'
+import { nip19 } from 'nostr-tools'
 import { marked } from 'marked'
 import { Button } from '@/components/ui/button'
 import { Card, CardContent } from '@/components/ui/card'
@@ -21,6 +22,15 @@ import { QrCode, ExternalLink } from 'lucide-vue-next'
 const router = useRouter()
 const isElectron = typeof window !== 'undefined' && window.electronAPI !== undefined
 
+// Build nprofile for Lightning.Pub (pubkey + relay hint)
+const lpNprofile = computed(() => {
+  const pubkey = import.meta.env.VITE_LIGHTNING_PUB_PUBKEY
+  if (!pubkey) return ''
+  const relayUrl = import.meta.env.VITE_RELAY_URL
+  const relays = relayUrl ? [relayUrl.replace('ws://', 'wss://')] : []
+  return nip19.nprofileEncode({ pubkey, relays })
+})
+
 interface SupportPage {
   id: string
   title: string
@@ -47,7 +57,13 @@ const defaultPages: SupportPage[] = [
 
 Tap a QR icon to scan and download a wallet.
 
-**Non-custodial** means you hold your own keys and have full control of your Bitcoin. **KYC-free** means no identity verification is required. Partial (~) means limits apply without verification.`,
+**Non-custodial** means you hold your own keys and have full control of your Bitcoin. **KYC-free** means no identity verification is required. Partial (~) means limits apply without verification.
+
+## Using ShockWallet with this ATM
+
+Scan the QR code below to add this ATM's Lightning node to your ShockWallet. This lets you send and receive sats directly through the ATM's payment system.
+
+[lp-nprofile]`,
   },
   {
     id: 'faq',
@@ -116,6 +132,7 @@ type Segment =
   | { type: 'qr'; content: string }
   | { type: 'table'; table: ParsedTable }
   | { type: 'qr-placeholder' }
+  | { type: 'lp-nprofile' }
 
 /** Parse markdown table into structured data */
 function parseMarkdownTable(tableLines: string[]): ParsedTable | null {
@@ -188,6 +205,9 @@ function parseContent(md: string): Segment[] {
       } else if (trimmed === '[operator-qr-placeholder]') {
         flushHtml()
         segments.push({ type: 'qr-placeholder' })
+      } else if (trimmed === '[lp-nprofile]') {
+        flushHtml()
+        segments.push({ type: 'lp-nprofile' })
       } else {
         htmlBlock += line + '\n'
       }
@@ -304,6 +324,33 @@ function goBack() {
             </CardContent>
           </Card>
 
+          <!-- Lightning.Pub nprofile QR -->
+          <Card v-else-if="seg.type === 'lp-nprofile'" class="my-6 mx-auto max-w-xs">
+            <CardContent class="flex flex-col items-center gap-3 p-6">
+              <template v-if="lpNprofile">
+                <div class="rounded-xl bg-white p-3">
+                  <QrcodeVue
+                    :value="lpNprofile"
+                    :size="180"
+                    level="L"
+                    render-as="svg"
+                    background="#ffffff"
+                    foreground="#000000"
+                  />
+                </div>
+                <span class="text-xs text-muted-foreground font-mono text-center break-all px-2">
+                  {{ lpNprofile.slice(0, 32) }}...
+                </span>
+              </template>
+              <template v-else>
+                <QrCode class="h-16 w-16 text-muted-foreground/30" />
+                <span class="text-sm text-muted-foreground/50 text-center">
+                  Lightning.Pub not configured
+                </span>
+              </template>
+            </CardContent>
+          </Card>
+
           <!-- Table with inline QR codes -->
           <div v-else-if="seg.type === 'table'" class="mb-8">
             <Table class="text-sm sm:text-base lg:text-xl w-full">