feat(wallet): hand live scanning to the companion's native camera when present

The scan/upload chooser (already on main) keeps the first move; when the
Android companion's window.ArchipelagoQr bridge exists, 'Scan with
camera' opens the native CameraX modal instead of getUserMedia — which
the companion's plain-http origin doesn't even have, so the button now
shows there too. Decodes come back via window.__archyQrResult, status
lines mirror out via setStatus, and stopScanning closes the native
modal once a code is accepted.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

neode-ui/src/components/WalletScanModal.vue

@@ -50,7 +50,9 @@
                   <path stroke-linecap="round" stroke-linejoin="round" stroke-width="1.5" d="M3 8V6a2 2 0 012-2h2M3 16v2a2 2 0 002 2h2m10-16h2a2 2 0 012 2v2m-4 12h2a2 2 0 002-2v-2M7 12h10" />
                 </svg>
                 <p class="text-sm text-white/60 text-center">How do you want to read the QR?</p>
-                <button v-if="!liveCameraUnavailable" @click="chooseCamera" class="glass-button w-full px-4 py-2.5 rounded-lg text-sm font-medium">
+                <!-- hasNativeQr: on the companion (plain http, no getUserMedia)
+                     the native bridge still provides a live camera -->
+                <button v-if="!liveCameraUnavailable || hasNativeQr" @click="chooseCamera" class="glass-button w-full px-4 py-2.5 rounded-lg text-sm font-medium">
                   Scan with camera
                 </button>
                 <button @click="photoInput?.click()" class="glass-button w-full px-4 py-2.5 rounded-lg text-sm font-medium">
@@ -271,6 +273,23 @@ type Rail = 'onchain' | 'lightning' | 'cashu' | 'fedimint'
 type Action = 'pay-invoice' | 'send-onchain' | 'redeem-token' | 'fedimint-join'
 type Pane = 'scan' | 'amount' | 'success'
 
+// JS bridge the Android companion injects: when present, live scanning is
+// delegated to a native camera modal (styled like this one) — the WebView's
+// getUserMedia preview lags, and over plain http it doesn't exist at all.
+// Decodes come back through the window.__archyQr* callbacks; status lines
+// (animated-QR progress, errors) mirror out to the native modal's strip.
+interface ArchipelagoQrBridge {
+  open(): void
+  setStatus(message: string, isError: boolean): void
+  close(): void
+}
+interface NativeWindow extends Window {
+  ArchipelagoQr?: ArchipelagoQrBridge
+  __archyQrResult?: (text: string) => void
+  __archyQrCancelled?: () => void
+}
+const nativeWin = window as NativeWindow
+
 const PRESETS = [21, 2100, 21000, 100000]
 
 const props = defineProps<{ show: boolean }>()
@@ -322,9 +341,24 @@ const autoStarting = ref(false)
 const scanChoice = ref<'unset' | 'camera'>('unset')
 
 function chooseCamera() {
+  if (startNativeScan()) return
   scanChoice.value = 'camera'
   void nextTick(() => startScanning())
 }
+
+// --- Native scanner (companion app) ---
+const hasNativeQr = !!nativeWin.ArchipelagoQr
+const nativeScanActive = ref(false)
+
+function startNativeScan(): boolean {
+  const bridge = nativeWin.ArchipelagoQr
+  if (!bridge) return false
+  nativeWin.__archyQrResult = (text: string) => handleScanned(text)
+  nativeWin.__archyQrCancelled = () => { nativeScanActive.value = false }
+  nativeScanActive.value = true
+  bridge.open()
+  return true
+}
 const scanStatus = ref('')
 const scanStatusIsError = ref(false)
 const cameraError = ref(false)
@@ -374,8 +408,20 @@ function stopScanning() {
   qrScanner.value?.destroy()
   qrScanner.value = null
   isScanning.value = false
+  if (nativeScanActive.value) {
+    nativeScanActive.value = false
+    nativeWin.ArchipelagoQr?.close()
+  }
 }
 
+// Mirror status lines onto the native modal while it's up — it covers the
+// page, so this strip is the only feedback the user can see.
+watch([scanStatus, scanStatusIsError], () => {
+  if (nativeScanActive.value) {
+    nativeWin.ArchipelagoQr?.setStatus(scanStatus.value, scanStatusIsError.value)
+  }
+})
+
 function submitPaste() {
   const text = pasteInput.value.trim()
   if (!text) return