fix(ui): seed QRs use the SeedQR standard so hardware wallets can scan them

Plain-text seed QRs didn't scan into Passport Prime — wallets that
import seeds by QR (Passport, SeedSigner, Keystone, Nunchuk, Sparrow)
expect the SeedQR standard: each BIP39 word as its zero-padded 4-digit
wordlist index, concatenated into a numeric QR.

- new utils/seedqr.ts encodes BIP39 words per the SeedSigner spec
  (@scure/bip39 wordlist; vector-checked abandon=0000, zoo=2047)
- new shared SeedRevealPanel (Words/QR tabs, tap-to-reveal blur) now
  backs the LND reveal AND the Settings→Backup recovery-phrase reveal,
  so every current and future seed reveal behaves the same
- onboarding seed + Settings reveal: QR defaults to SeedQR with a
  plain-text toggle
- LND seed stays plain-text-only with an explicit note: aezeed is not
  BIP39 and only restores into LND-based wallets (Zeus/Blixt/another
  node) — SeedQR-encoding it would just mislead

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

neode-ui/src/components/SeedRevealPanel.vue

@@ -0,0 +1,124 @@
+<template>
+  <div>
+    <div class="flex gap-1 mb-3 p-1 bg-white/5 rounded-lg">
+      <button
+        v-for="tab in ([{ key: 'words', label: 'Words' }, { key: 'qr', label: 'QR code' }] as const)"
+        :key="tab.key"
+        type="button"
+        @click="seedTab = tab.key"
+        class="flex-1 px-2 py-1.5 rounded text-xs font-medium transition-colors"
+        :class="seedTab === tab.key ? 'bg-white/15 text-white' : 'text-white/50 hover:text-white/80'"
+      >{{ tab.label }}</button>
+    </div>
+
+    <template v-if="seedTab === 'words'">
+      <p class="text-sm text-white/60 mb-3">Write these down and store them offline. Tap to {{ hidden ? 'reveal' : 'hide' }}.</p>
+      <div class="relative">
+        <div
+          class="grid grid-cols-2 sm:grid-cols-3 gap-2 p-3 bg-white/5 rounded-lg transition-all select-text"
+          :class="hidden ? 'blur-md' : ''"
+          @click="hidden = !hidden"
+        >
+          <div v-for="(w, i) in words" :key="i" class="flex items-center gap-1.5 text-sm">
+            <span class="text-white/30 text-xs w-5 text-right">{{ i + 1 }}.</span>
+            <span class="text-white font-mono">{{ w }}</span>
+          </div>
+        </div>
+        <button v-if="hidden" type="button" class="absolute inset-0 flex items-center justify-center text-xs text-white/70 font-medium" @click="hidden = false">Tap to reveal</button>
+      </div>
+    </template>
+
+    <template v-else>
+      <p class="text-sm text-white/60 mb-3">
+        {{ aezeed ? 'Scan to copy the words into another device.' : 'Scan into a wallet that imports seeds by QR.' }}
+        Tap to {{ hidden ? 'reveal' : 'hide' }}.
+      </p>
+      <div class="relative">
+        <div
+          class="flex justify-center p-3 bg-white/5 rounded-lg transition-all"
+          :class="hidden ? 'blur-md' : ''"
+          @click="hidden = !hidden"
+        >
+          <canvas ref="qrCanvas" class="rounded-lg bg-white p-2"></canvas>
+        </div>
+        <button v-if="hidden" type="button" class="absolute inset-0 flex items-center justify-center text-xs text-white/70 font-medium" @click="hidden = false">Tap to reveal</button>
+      </div>
+      <div v-if="!aezeed && seedQrAvailable" class="flex justify-center mt-2">
+        <div class="flex p-0.5 bg-white/5 rounded-md">
+          <button
+            v-for="f in ([{ key: 'seedqr', label: 'SeedQR' }, { key: 'text', label: 'Plain text' }] as const)"
+            :key="f.key"
+            type="button"
+            @click="qrFormat = f.key"
+            class="px-2.5 py-1 rounded text-[11px] font-medium transition-colors"
+            :class="qrFormat === f.key ? 'bg-white/15 text-white' : 'text-white/50 hover:text-white/80'"
+          >{{ f.label }}</button>
+        </div>
+      </div>
+      <p class="text-xs text-white/40 mt-2">
+        <template v-if="aezeed">
+          The code contains your seed words as plain text — treat it exactly like the words
+          themselves. Note: this is an LND <span class="font-mono">aezeed</span>, not a BIP39
+          phrase — it restores into LND-based wallets (Zeus, Blixt, another Archipelago node),
+          not into hardware wallets like Passport.
+        </template>
+        <template v-else-if="qrFormat === 'seedqr'">
+          SeedQR — scans into Passport, SeedSigner, Keystone and other wallets that import
+          seeds by QR. Treat this code exactly like the words themselves.
+        </template>
+        <template v-else>
+          Plain text words — for wallets that read the phrase as text. Treat this code exactly
+          like the words themselves.
+        </template>
+      </p>
+    </template>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref, watch, nextTick } from 'vue'
+
+// Shared seed reveal body: Words / QR code tabs behind a tap-to-reveal blur.
+// Words are always the first view. For BIP39 seeds the QR defaults to the
+// SeedQR standard (4-digit wordlist indices — what Passport Prime, SeedSigner,
+// Keystone etc. import), with a plain-text option. `aezeed` seeds (LND) are
+// NOT BIP39 and no hardware wallet can import them, so they only ever get the
+// plain-text QR plus an explanation — SeedQR-encoding one would be dishonest.
+const props = defineProps<{ words: string[]; aezeed?: boolean }>()
+
+const seedTab = ref<'words' | 'qr'>('words')
+const qrFormat = ref<'seedqr' | 'text'>(props.aezeed ? 'text' : 'seedqr')
+const seedQrAvailable = ref(!props.aezeed)
+const hidden = ref(true)
+const qrCanvas = ref<HTMLCanvasElement | null>(null)
+
+async function renderQr() {
+  await nextTick()
+  if (!qrCanvas.value || props.words.length === 0) return
+  try {
+    let payload = props.words.join(' ')
+    if (!props.aezeed && qrFormat.value === 'seedqr') {
+      const { toSeedQrDigits } = await import('@/utils/seedqr')
+      const digits = await toSeedQrDigits(props.words)
+      if (digits) {
+        payload = digits
+      } else {
+        // Not a BIP39 phrase after all — only plain text is honest.
+        seedQrAvailable.value = false
+        qrFormat.value = 'text'
+        return // the qrFormat watcher re-renders as text
+      }
+    }
+    const QRCode = await import('qrcode')
+    await QRCode.toCanvas(qrCanvas.value, payload, { width: 260, margin: 1 })
+  } catch { /* QR is a convenience — the words remain authoritative */ }
+}
+watch(seedTab, (t) => { if (t === 'qr') void renderQr() })
+watch(qrFormat, () => { if (seedTab.value === 'qr') void renderQr() })
+watch(() => props.words, () => {
+  seedTab.value = 'words' // fresh reveal always shows words first
+  hidden.value = true
+  seedQrAvailable.value = !props.aezeed
+  qrFormat.value = props.aezeed ? 'text' : 'seedqr'
+})
+</script>