feat: show seed word in browser (for devices with no display)

lnbits/extensions/watchonly/static/components/serial-signer/serial-signer.html

@@ -393,9 +393,23 @@
     </q-card>
   </q-dialog>
 
-  <q-dialog v-model="hww.showSeedDialog" position="top">
+  <q-dialog v-model="hww.showSeedDialog" @hide="closeSeedDialog" position="top">
     <q-card class="q-pa-lg q-pt-xl">
-      <span>Check word at position {{hww.seedWordPosition}} on display</span>
+      <span>Check word at position {{hww.seedWordPosition}} on device</span>
+      <div class="row q-mt-lg">
+        <div class="col-12">
+          <q-toggle
+            label="Show Seed Word"
+            color="secodary"
+            v-model="hww.showSeedWord"
+          ></q-toggle>
+        </div>
+      </div>
+      <div v-if="hww.showSeedWord" class="row q-mt-lg">
+        <div class="col-12">
+          <q-input readonly v-model.trim="hww.seedWord"></q-input>
+        </div>
+      </div>
 
       <div class="row q-mt-lg">
         <div class="col-4">

lnbits/extensions/watchonly/static/components/serial-signer/serial-signer.js

@@ -38,6 +38,8 @@ async function serialSigner(path) {
           psbtSentResolve: null,
           xpubResolve: null,
           seedWordPosition: 1,
+          seedWord: null,
+          showSeedWord: false,
           showSeedDialog: false,
           // config: null,
 
@@ -374,6 +376,10 @@ async function serialSigner(path) {
           })
         }
       },
+      closeSeedDialog: function () {
+        this.hww.seedWord = null
+        this.hww.showSeedWord = false
+      },
       hwwConfirmNext: async function () {
         this.hww.confirm.outputIndex += 1
         if (this.hww.confirm.outputIndex >= this.tx.outputs.length) {
@@ -817,7 +823,8 @@ async function serialSigner(path) {
         await this.sendCommandSecure(COMMAND_SEED, [this.hww.seedWordPosition])
       },
       handleShowSeedResponse: function (res = '') {
-        const args = res.trim().split(' ')
+        const [pos, word] = res.trim().split(' ')
+        this.hww.seedWord = `${pos}. ${word}`
       },
       hwwRestore: async function () {
         try {