On a domain, show the code and nothing else

Build 123. 122 taught the banner and the QR about the public address but left
the interface picker underneath them untouched, so the panel still listed
10.6.5.55 and 10.1.7.39 with one marked IN USE — numbers that no longer point
anywhere anybody is being sent, directly under a banner naming the domain.

Those rows exist to choose which interface the code encodes, which is a
question only a LAN setup has: with a public address set the code points at the
domain whichever row is picked. They are hidden now, and a LAN-only campus is
unaffected.

Printable poster is replaced by Save QR image. The poster people actually print
is made in their own design tool, and what they need from the app is the code
as a file — a 512px SVG, so it scales to any size without going soft. The
built-in poster page is untouched at /poster for anyone who wants it.

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

app/engine.js

@@ -3508,14 +3508,50 @@ function shareChoice() {
   };
 }
 
-function shareBase() {
+/* This Mac on the church network. The operator page lives here and NOWHERE
+   else: it returns 404 to anything arriving through a proxy, by design. */
+function lanBase() {
   const c = shareChoice();
   if (!c || c.none) return '';
   return 'http://' + c.addr.address + ':' + state.local.port;
 }
 
+/*
+ * WHAT THE CONGREGATION OPENS.
+ *
+ * A church that has put this on a domain has said so in the operator page's
+ * Public address, and from that moment the LAN address is the wrong thing to
+ * print: it is not what is on the poster, not what the QR should encode, and
+ * not what someone off the building's wifi can reach. The app window went on
+ * showing the IP anyway, because this half of it never read that setting --
+ * the operator page honoured it and the main window did not, so the two
+ * disagreed about the one fact they both exist to display.
+ */
+function publicBaseConfigured() {
+  const u = opConfig && typeof opConfig.publicUrl === 'string' ? opConfig.publicUrl.trim() : '';
+  return u ? u.replace(/\/+$/, '') : '';
+}
+
+function shareBase() {
+  return publicBaseConfigured() || lanBase();
+}
+
 function renderQrWarning() {
   const el = $('qrWarn');
+  /*
+   * On a domain the warnings below are about an address nobody is being
+   * given any more. Saying "Wi-Fi is down, phones cannot reach the code"
+   * while the code points at a proxy would send the desk after the wrong
+   * thing entirely.
+   */
+  const pub = publicBaseConfigured();
+  if (pub) {
+    el.hidden = false;
+    el.textContent = 'The code points at ' + pub + ', set as the public address. ' +
+      'This Mac still has to be reachable from there; its own address is ' +
+      (lanBase() || 'unavailable') + '.';
+    return;
+  }
   const c = shareChoice();
   if (!c) { el.hidden = true; return; }
 
@@ -3566,6 +3602,26 @@ function renderShare() {
   const list = state.local.addresses || [];
   const box = $('addrList');
   box.textContent = '';
+  /*
+   * WHICH INTERFACE THE QR USES IS A QUESTION ONLY A LAN SETUP HAS.
+   *
+   * These rows let the operator pick the address the code points at. Once a
+   * public address is configured the code points at the domain whatever they
+   * pick, so the list is a row of numbers that do nothing — and the one
+   * marked IN USE is not the address anyone is being given. Hide it.
+   */
+  const addrBox = $('addrList');
+  addrBox.hidden = !!publicBaseConfigured();
+  if (addrBox.hidden) {
+    /* Still draw the code itself — it is the only thing left in this panel. */
+    const only = shareBase();
+    $('qr').src = only
+      ? 'http://127.0.0.1:' + state.local.port + '/qr.svg?url=' + encodeURIComponent(only + '/')
+      : '';
+    renderQrWarning();
+    renderOperatorUrl();
+    return;
+  }
 
   /* Mark the row the QR is actually using, not the row that was saved — when
      a lease moves those are two different things and the saved one is gone. */
@@ -3607,8 +3663,22 @@ $('copyAddr').addEventListener('click', () => {
     .catch((err) => log('could not copy: ' + err.message, 'err'));
 });
 
-$('openPoster').addEventListener('click', () => {
+/*
-  window.open('http://127.0.0.1:' + state.local.port + '/poster', '_blank');
+ * The QR itself, saved as a file, because the poster people actually print
+ * is made in their own design tool. The built-in poster page is still there
+ * at /poster for anyone who wants it; it is just not what this button does.
+ */
+$('saveQr').addEventListener('click', () => {
+  const base = shareBase();
+  if (!base) { log('no address to encode yet', 'err'); return; }
+  const a = document.createElement('a');
+  a.href = 'http://127.0.0.1:' + state.local.port + '/qr.svg?url=' +
+           encodeURIComponent(base + '/');
+  a.download = 'church-translate-qr.svg';
+  document.body.appendChild(a);
+  a.click();
+  a.remove();
+  log('saved the QR for ' + base + '/', 'ok');
 });
 $('openOperator').addEventListener('click', () => {
   window.open('http://127.0.0.1:' + state.local.port + '/operator', '_blank');
@@ -3665,7 +3735,8 @@ function renderBuildTag() {
 }
 
 function renderOperatorUrl() {
-  const base = shareBase();
+  /* Deliberately lanBase, not shareBase: over a proxy /operator is a 404. */
+  const base = lanBase();
   $('opPageUrl').textContent = base ? base + '/operator' : 'no network';
 }
 
@@ -3968,6 +4039,7 @@ async function loadOperator() {
   try {
     const j = await opApi('/api/config');
     opConfig = j.config;
+    renderShare();   /* publicUrl may have just arrived */
     clearTimeout(opLoadTimer); opLoadTimer = null;   // it answered; stop retrying
     opRetryMs = 0;
     renderOpLanguages();
@@ -4022,6 +4094,7 @@ async function opSave(patch, okMsg) {
   try {
     const j = await opApi('/api/config', { method: 'POST', body: JSON.stringify(patch) });
     opConfig = j.config;
+    renderShare();   /* publicUrl may have just arrived */
     if (okMsg) log(okMsg, 'ok');
     return j;
   } catch (e) { log('could not save: ' + e.message, 'err'); throw e; }

app/index.html

@@ -433,7 +433,7 @@
       <div id="addrList" class="addrlist"></div>
       <div class="railbtns">
         <button class="btn btn-primary" id="copyAddr">Copy address</button>
-        <button class="btn" id="openPoster">Printable poster</button>
+        <button class="btn" id="saveQr">Save QR image</button>
       </div>
 
       <h3 class="subhead">Operator page</h3>

app/package.json

@@ -2,7 +2,7 @@
   "name": "church-translate-engine",
   "productName": "Church Translate",
   "version": "3.23.2",
-  "buildNumber": 121,
+  "buildNumber": 123,
   "private": true,
   "description": "Live sermon translation — self-contained: captures audio, transcribes, translates, and serves the congregation page itself",
   "main": "main.js",
@@ -106,7 +106,7 @@
       ]
     },
     "asar": false,
-    "buildVersion": "121",
+    "buildVersion": "123",
     "win": {
       "target": [
         {