Stop the stream seeking against itself, and stop the desk scrolling itself

Build 126. Two reports, unrelated to each other.

IPHONES REPEATING AND SKIPPING PARTS OF EVERY SENTENCE.

DRIFT_LAND was 0.6 s and one segment is 0.697 s, so the position the player
was being held at sat INSIDE the newest segment — a point it very often did
not have yet. It got dragged to the edge, ran out of audio and stalled. Then
'stalled' and 'waiting' were both wired to seekLive(), and a seek on a live
HLS stream makes the element re-buffer, which raises those same two events. So
the correction caused the stall that caused the correction. On Safari, where
HLS is native and a seek lands on a segment boundary, each turn of that loop
replays or drops a piece of a sentence — which is exactly what was described.

Three changes, all of them about not fighting the player: those two events no
longer seek, the target is three segments back (~2.1 s, what an HLS player
picks for itself on a live playlist), and a correction now has 5 s to settle
before another may run. Costs about 1.5 s of extra delay. A listener a second
further behind is following the service; one whose audio keeps jumping
backwards is not.

NOT YET CONFIRMED ON A REAL IPHONE — the mechanism is read off the code and
the measured segment length, and the next service is the test.

CANNOT SCROLL THE MONITOR WHILE LIVE.

Four boxes ended their update with box.scrollTop = box.scrollHeight,
unconditionally, so every sentence yanked the view back to the live edge and
reading back was impossible. They now follow the bottom only while the
operator is already at the bottom, and resume when they return — nothing to
press either way. Trimming the top is held off while they are scrolled away
too, since dropping old lines moves the text being read; the cap comes back
the moment they return, with a ceiling so nothing grows all service.

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

app/engine.js

@@ -190,9 +190,64 @@ const state = {
 
   /* health counters, reported to the operator page */
   degradedFinals: 0,         // finals that shipped with fewer languages (stale)
-  captionOnlyFinals: 0       // finals that shipped with no translations at all
+  captionOnlyFinals: 0,      // finals that shipped with no translations at all
+  captionOnlyAt: 0,          // when the last one happened
+  degradedAt: 0
 };
 
+/*
+ * FOLLOW THE BOTTOM ONLY WHILE THE OPERATOR IS AT THE BOTTOM.
+ *
+ * Every one of these boxes used to end its update with
+ * `box.scrollTop = box.scrollHeight`, unconditionally. While the service is
+ * running that fires on every sentence, so scrolling back to re-read what was
+ * just said was impossible: the box yanked itself to the live edge a fraction
+ * of a second later, every time. Reported from the desk as "can't scroll on
+ * what's being said when it's live", which is exactly what it was.
+ *
+ * A box follows the live edge until the operator scrolls away from it, and
+ * starts following again when they come back to it. Nothing has to be pressed
+ * to get out, and nothing has to be pressed to get back in.
+ *
+ * The slack matters. A programmatic jump to the bottom also raises a scroll
+ * event, and it lands AT the bottom, so sticking survives its own scrolling.
+ * Sub-pixel layout and a growing last line can leave a couple of pixels
+ * behind, which with a zero threshold would unstick the box on its own output.
+ */
+/*
+ * Trimming the TOP of a box the operator is reading moves the text under
+ * their eyes — the other half of "it keeps jumping". While they are scrolled
+ * away the cap is suspended, so the lines they are looking at stay put; when
+ * they return to the live edge the backlog is trimmed in one go. The ceiling
+ * keeps a box that is left scrolled up all service from growing without end.
+ */
+function trimTop(box, cap) {
+  if (!box) return;
+  const held = box.dataset.stick === '0';
+  const limit = held ? cap * 6 : cap;
+  while (box.children.length > limit) box.removeChild(box.firstChild);
+}
+
+const STICK_SLACK_PX = 48;
+const stickWired = new WeakSet();
+
+function followBottom(box) {
+  if (!box) return;
+  if (!stickWired.has(box)) {
+    stickWired.add(box);
+    box.dataset.stick = '1';
+    box.addEventListener('scroll', () => {
+      const atBottom =
+        box.scrollHeight - box.scrollTop - box.clientHeight <= STICK_SLACK_PX;
+      box.dataset.stick = atBottom ? '1' : '0';
+    }, { passive: true });
+  }
+  /* Scrolled away: leave the view exactly where they put it. New content
+     grows BELOW the viewport, so not touching scrollTop is what holds the
+     reader's place — there is nothing else to do here. */
+  if (box.dataset.stick !== '0') box.scrollTop = box.scrollHeight;
+}
+
 // ────────────────────────────────────────────────────────── logging
 
 function log(msg, kind) {
@@ -206,8 +261,8 @@ function log(msg, kind) {
   if (kind) line.className = kind;
   line.textContent = new Date().toLocaleTimeString() + '  ' + msg;
   el.appendChild(line);
-  while (el.children.length > 200) el.removeChild(el.firstChild);
+  trimTop(el, 200);
-  el.scrollTop = el.scrollHeight;
+  followBottom(el);
 }
 
 function hero(stateName, title, body) {
@@ -891,12 +946,54 @@ async function respawnWorker(worker) {
         log('the speech model is too heavy for this machine — switching to ' +
             lighter.split('/').pop(), 'err');
       }
+      /*
+       * A LIGHTER MODEL GETS THE PREVIEW'S DTYPE, NOT THE BIG ONE'S.
+       *
+       * asrDtype is chosen for the accurate model and its weights are cached against
+       * it. Reusing it when stepping down asks for a variant that was never
+       * downloaded — and those weights live in the browser cache, with no network at
+       * a venue — so the step-down failed and the ladder could not move at all.
+       *
+       * MEASURED on a campus Mac: the cache held whisper-large-v3-turbo as
+       * encoder_model_q4f16.onnx (its asrDtype) and whisper-small as
+       * encoder_model_fp16.onnx (the preview's). Stepping down asked for
+       * whisper-small at q4f16, a file that is not there; it went to the network,
+       * failed, and logged "Unsupported model type: whisper" three times a minute
+       * for ever while the service sat dead.
+       *
+       * The preview runs whisper-small on exactly these settings every service, so
+       * they are the one combination this machine is known to be able to load.
+       */
+      const stepDtype = lighter
+        ? resolveDtype(cfg.asrFastDtype, { encoder_model: 'fp16', decoder_model_merged: 'q4' })
+        : resolveDtype(cfg.asrDtype, { encoder_model: 'fp16', decoder_model_merged: 'q4' });
       state.asrWorker = await loadWorkerWithFallback('speech', 'automatic-speech-recognition',
         state.asrModelInUse || cfg.asrModel,
-        resolveDtype(cfg.asrDtype, { encoder_model: 'fp16', decoder_model_merged: 'q4' }),
+        stepDtype,
         { encoder_model: 'q4', decoder_model_merged: 'q4' });
       log('speech model restarted' + (lighter ? ' on ' + lighter.split('/').pop() : ''), 'ok');
       state.slowRun = 0;
+      if (lighter) {
+        /*
+         * THROW AWAY THE BACKLOG THAT CAUSED THIS, AND LET THE NEW MODEL SETTLE.
+         *
+         * Swapping the model does nothing about the queue that triggered the swap.
+         * Those chunks are already past the caption-only cutoff, so they can no
+         * longer be translated in time and are worth nothing to the room — but the
+         * first of them gets handed to a model that has just loaded, takes the full
+         * worker timeout, and trips the absolute rule. MEASURED: a campus Mac fell
+         * large-v3-turbo -> small -> base in 34 seconds exactly that way, landing on
+         * a model SLOWER than the one it started from.
+         *
+         * So drop them, and refuse to step down again for a grace window, so the new
+         * model is judged on sentences it was actually given.
+         */
+        const dropped = queue.length;
+        queue.length = 0;
+        state.steppedDownAt = Date.now();
+        if (dropped) log('dropped ' + dropped + ' stale sentence' + (dropped === 1 ? '' : 's') +
+                         ' the old model never reached', 'warn');
+      }
     }
   } catch (err) {
     log('model restart failed: ' + err.message, 'err');
@@ -1794,6 +1891,7 @@ async function pump() {
 
   state.busy = true;
   const started = Date.now();
+  let jobAudioMs = 0;
   try {
     /* job.at is when the audio ENDED. Live translation of stale audio is
        worthless, but the WORDS are not: however old the job, it still gets
@@ -1805,6 +1903,9 @@ async function pump() {
     /* Near-silence telemetry (log-only this release): a chunk whose average
        level barely clears the noise floor is hallucination fuel. */
     const audio = flatten(job.frames);
+    /* How much speech this chunk actually holds. The step-down below compares
+       against it, because "slow" only means anything relative to the audio. */
+    jobAudioMs = (audio.length / SAMPLE_RATE) * 1000;
     let sum = 0;
     for (let i = 0; i < audio.length; i += 4) sum += audio[i] * audio[i];
     const meanRms = Math.sqrt(sum / Math.ceil(audio.length / 4));
@@ -1845,15 +1946,33 @@ async function pump() {
       const sentences = collapseLoops(splitSentences(text));
 
       let targets = orderedTargets();
-      if (ageSec > 12) {
+      /*
+       * SKIPPING A TRANSLATION ONLY BUYS SOMETHING IF THERE IS A QUEUE TO DRAIN.
+       *
+       * Dropping the translations of stale audio is how the app catches up: the
+       * listener has moved on, so the work is wasted and the time is better spent on
+       * the sentences behind it. That reasoning needs a backlog. With nothing waiting
+       * behind it, skipping costs the room a sentence and saves nothing at all.
+       *
+       * MEASURED: a campus Mac took one 16 s stall — two Screen Sharing sessions
+       * competing for the machine — and skipped that sentence's translations with an
+       * EMPTY queue. The room lost a line of the sermon to a catch-up that had
+       * nothing to catch up on.
+       */
+      if (ageSec > 12 && queue.length > 0) {
         targets = [];
         state.captionOnlyFinals++;
-        log('audio ' + ageSec.toFixed(0) + 's stale — caption only, translations skipped', 'err');
+        state.captionOnlyAt = Date.now();
+        log('audio ' + ageSec.toFixed(0) + 's stale with ' + queue.length + ' waiting — ' +
+            'caption only, translations skipped', 'err');
+      } else if (ageSec > 12) {
+        /* Late, but nothing is behind it: say so, and translate it anyway. */
+        log('audio ' + ageSec.toFixed(0) + 's late, but nothing is queued — translating it anyway', 'warn');
       } else if (ageSec > 6) {
         const listening = new Set((state.byLanguage || []).map((r) => r.lang));
         const before = targets.length;
         targets = targets.filter((t) => listening.has(t));
-        if (targets.length < before) state.degradedFinals++;
+        if (targets.length < before) { state.degradedFinals++; state.degradedAt = Date.now(); }
       }
 
       /* The segment's own loudness, measured once and shared by every sentence
@@ -1908,11 +2027,56 @@ async function pump() {
      * talk, and the backlog only grows — step down before the service is lost
      * rather than after. Measured on the Intel laptop: 12-25 s, every sentence.
      */
-    if (took > 8000) {
+    /*
+     * SLOWER THAN THE AUDIO IT COVERS — not slower than some constant.
+     *
+     * This used to fire only past 8 s, on the reasoning that 8 s meant slower
+     * than people talk. That was true when a chunk could be 8 s long. Chunks
+     * are capped at HARD_CUT_MAX, 5.5 s, so a 4.5 s chunk taking 4.3 s is
+     * already losing ground and never came near the old threshold.
+     *
+     * MEASURED on a campus M4 Pro: every sentence 4.2-4.7 s against roughly
+     * 4-5 s of audio, a queue 46 deep and a lag of 152 s still climbing — with
+     * nobody listening and no language being translated, so this was
+     * transcription alone. The one mechanism built to catch exactly that could
+     * not fire, because 4.4 s is not 8 s.
+     *
+     * The queue test is what separates "this machine cannot keep up" from one
+     * slow sentence: a backlog that is three deep and being fed faster than it
+     * drains does not recover on its own.
+     */
+    /*
+     * SLOWER THAN THE AUDIO IT COVERS, AND LANDING LATE.
+     *
+     * This used to fire only past 8 s, on the reasoning that 8 s meant slower
+     * than people talk. That held when a chunk could be 8 s long; chunks are
+     * capped at HARD_CUT_MAX, 5.5 s, so a 4.4 s sentence is already losing and
+     * never came near the old threshold.
+     *
+     * Both numbers below were measured on a campus M4 Pro, and the second one
+     * only after a first attempt got it wrong. 0.85, because that Mac ran 4.4 s
+     * against 4.5 s of audio — nominally FASTER than real time while losing
+     * badly, since the work outside this timer (segmenting, the preview model
+     * sharing the GPU, the scheduler) loses on its own.
+     *
+     * The second test was a queue depth, and watching that Mac go red disproved
+     * it: the queue sat at 2-3 while the lag held at 15 s and the verdict was
+     * already red. A machine can be persistently late without ever stacking work
+     * up — it finishes each sentence just slightly too slowly, for ever. So the
+     * test is how far behind the speaker the sentence actually landed, which is
+     * what the operator is complaining about in the first place.
+     */
+    /* A model that loaded seconds ago has not had a fair sentence yet. */
+    const settling = state.steppedDownAt && (Date.now() - state.steppedDownAt) < STEP_SETTLE_MS;
+    const behindMs = Date.now() - job.at;
+    const losingGround = jobAudioMs > 0 && took > jobAudioMs * 0.85 && behindMs > 8000;
+    if (!settling && (took > 8000 || losingGround)) {
       state.slowRun = (state.slowRun || 0) + 1;
       if (state.slowRun >= 3 && !respawning && lighterAsr(state.asrModelInUse || state.cfg.asrModel)) {
         state.slowRun = 0;
-        log('transcription is slower than people are speaking — stepping down to a lighter model', 'err');
+        log('transcription is slower than people are speaking (' + took + ' ms for ' +
+            Math.round(jobAudioMs) + ' ms of audio, ' + Math.round(behindMs / 1000) + 's behind) — ' +
+            'stepping down to a lighter model', 'err');
         respawnWorker(state.asrWorker);
       }
     } else state.slowRun = 0;
@@ -2360,8 +2524,8 @@ function monitorFinal(cid, text) {
   monRows.set(cid, el);
   /* Neither the map nor the box may grow for the length of a service. */
   while (monRows.size > 60) monRows.delete(monRows.keys().next().value);
-  while (box.children.length > 24) box.removeChild(box.firstChild);
+  trimTop(box, 24);
-  box.scrollTop = box.scrollHeight;
+  followBottom(box);
 }
 
 /*
@@ -2403,7 +2567,7 @@ function monitorTranslation(cid, lang, text) {
     row.classList.add('dropped');
   }
   const box = $('monitor');
-  if (box) box.scrollTop = box.scrollHeight;
+  followBottom(box);
 }
 
 /*
@@ -2423,6 +2587,11 @@ function monitorTranslation(cid, lang, text) {
  * It says it once per episode, and names both numbers so the operator can act
  * on it rather than go looking.
  */
+/* How long a freshly swapped speech model is left alone. Long enough to cover a
+   cold first inference, short enough that a genuinely hopeless model still falls
+   through the ladder within a sentence or two. */
+const STEP_SETTLE_MS = 20000;
+
 const DEAF_AFTER_MS = 90000;
 setInterval(() => {
   try {
@@ -2465,9 +2634,9 @@ function showMonitor(text, isPartial, langCount) {
     sub.textContent = langCount + ' language' + (langCount === 1 ? '' : 's') + ' · ' + state.lagMs + ' ms';
     el.appendChild(sub);
     box.appendChild(el);
-    while (box.children.length > 30) box.removeChild(box.firstChild);
+    trimTop(box, 30);
   }
-  box.scrollTop = box.scrollHeight;
+  followBottom(box);
 }
 
 // ────────────────────────────────────────────────────────── church server
@@ -2662,6 +2831,7 @@ function goLive(on) {
   state.live = on;
   if (on) {
     state.degradedFinals = 0; state.captionOnlyFinals = 0; state.fragmentFinals = 0;
+    state.captionOnlyAt = 0; state.degradedAt = 0;
     /* The watchdog measures from the start of the service, not from the last
        sentence of the previous one. */
     state.lastFinalAt = Date.now();
@@ -2736,6 +2906,10 @@ function reportStatus() {
       queue: queue.length,
       degradedFinals: state.degradedFinals,
       captionOnlyFinals: state.captionOnlyFinals,
+      /* WHEN, not just how many — the verdict needs to know whether this is
+         happening now or happened once an hour ago. */
+      captionOnlyAt: state.captionOnlyAt || 0,
+      degradedAt: state.degradedAt || 0,
       fragmentFinals: state.fragmentFinals || 0,
       cloud: state.cloudStats || null
     }
@@ -2983,14 +3157,26 @@ async function downloadUpdate() {
   try {
     const r = await window.engineHost.updateDownload(updFound.asset.url, updFound.asset.name);
     if (!r.ok) { $('updProgress').textContent = r.error || 'Download failed.'; btn.disabled = false; return; }
-    $('updProgress').textContent = 'Saved to Downloads.';
+      $('updProgress').textContent = 'Downloaded. Installing\u2026';
-    /* Say what is left to do. Nothing installs itself here on purpose — see
-       the note on the main-process side. */
-    $('updWhat').textContent = 'Downloaded ' + updFound.tag + ' (' + fmtMB(r.bytes) + '). ' +
-      'Quit Church Translate, open the disk image, and drag the app over the one in ' +
-      'Applications. Your settings, models and voices are untouched.';
       log('update ' + updFound.tag + ' downloaded to ' + r.path, 'ok');
+
+      /*
+       * Straight into the install. The app quits, a helper swaps the bundle and
+       * reopens it — so from here the window closing IS the update working, and
+       * saying so before it happens stops that looking like a crash.
+       */
+      $('updWhat').textContent = 'Installing ' + updFound.tag + '. Church Translate will close and ' +
+        'reopen by itself in a few seconds. Your settings, models and voices are untouched.';
+      const ins = await window.engineHost.updateInstall(r.path);
+      if (!ins || !ins.ok) {
+        /* Still useful: the file is downloaded, so fall back to the manual route
+           rather than leaving them with nothing. */
+        $('updProgress').textContent = (ins && ins.error) || 'Could not install.';
+        $('updWhat').textContent = 'Downloaded, but it could not install itself. Quit Church ' +
+          'Translate, open the disk image in Downloads, and drag the app over the one in Applications.';
         try { await window.engineHost.updateReveal(r.path); } catch (_) {}
+        btn.disabled = false;
+      }
   } catch (e) {
     $('updProgress').textContent = 'Download failed: ' + e.message;
     btn.disabled = false;
@@ -3375,14 +3561,50 @@ 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; }
 
@@ -3433,6 +3655,26 @@ 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. */
@@ -3474,8 +3716,40 @@ $('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', async () => {
+  const base = shareBase();
+  if (!base) { log('no address to encode yet', 'err'); return; }
+  /*
+   * Fetch the code and hand the browser a BLOB rather than linking straight at
+   * the server. This window is served from the asset port and the QR comes off
+   * the congregation port, so a plain <a download> is CROSS-ORIGIN — the
+   * download attribute is ignored and the window navigates to the image
+   * instead. With no back button, no reload item and no address bar, that
+   * strands the operator on a full-screen QR with no way out; build 123 did
+   * exactly that to a booth Mac. A blob: URL is same-origin, so it downloads.
+   */
+  const url = 'http://127.0.0.1:' + state.local.port + '/qr.svg?url=' +
+              encodeURIComponent(base + '/');
+  try {
+    const r = await fetch(url, { cache: 'no-store' });
+    if (!r.ok) throw new Error('the server answered ' + r.status);
+    const href = URL.createObjectURL(await r.blob());
+    const a = document.createElement('a');
+    a.href = href;
+    a.download = 'church-translate-qr.svg';
+    document.body.appendChild(a);
+    a.click();
+    a.remove();
+    setTimeout(() => URL.revokeObjectURL(href), 10000);
+    log('saved the QR for ' + base + '/ to Downloads', 'ok');
+  } catch (err) {
+    log('could not save the QR: ' + err.message, 'err');
+  }
 });
 $('openOperator').addEventListener('click', () => {
   window.open('http://127.0.0.1:' + state.local.port + '/operator', '_blank');
@@ -3532,7 +3806,8 @@ 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';
 }
 
@@ -3835,6 +4110,7 @@ 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();
@@ -3889,6 +4165,7 @@ 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

@@ -391,7 +391,7 @@
           <div id="updFound" hidden>
             <p class="hint" id="updWhat"></p>
             <div class="row">
-              <button class="btn" id="updGet">Download it</button>
+              <button class="btn" id="updGet">Download and install</button>
               <span class="hint" id="updProgress"></span>
             </div>
             <details id="updNotesBox"><summary class="hint">What changed</summary>
@@ -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/main.js

@@ -440,6 +440,11 @@ function startServer() {
     execPath: nodeBin,
     env: Object.assign({}, process.env, {
       CT_FFMPEG: ffmpegPathForChildren(),
+      /* So /healthz can report the APP’s version rather than only an asset
+         hash. A campus Mac’s build was otherwise unknowable from the network,
+         which made confirming an update a matter of inference. */
+      CT_APP_VERSION: appBuild().version,
+      CT_APP_BUILD: appBuild().build,
       PORT: String(port),
       DATA_DIR: dataDir(),
       /* Where the spoken clips land, so the server can hand them to phones. */
@@ -657,6 +662,27 @@ function createWindow() {
              : '/index.html';
   win.loadURL(assetOrigin + page);
 
+  /*
+   * NOTHING replaces the app in this window. There is no back button, no
+   * reload item and no address bar, so a window that leaves the app page is a
+   * window the operator cannot get back from — which is precisely how build
+   * 123 stranded a booth Mac on a full-screen QR image. Our own pages still
+   * open as their OWN windows through setWindowOpenHandler below; this only
+   * refuses to replace the app itself, and sends anything external to the
+   * browser where it belongs.
+   */
+  win.webContents.on('will-navigate', (e, url) => {
+    if (url === assetOrigin + page) return;     /* reloading ourselves is fine */
+    e.preventDefault();
+    console.error('[main] refused to navigate the app window to ' + url);
+    let local = false;
+    try {
+      const u = new URL(url);
+      local = (u.hostname === '127.0.0.1' || u.hostname === 'localhost');
+    } catch (_) { local = false; }
+    if (!local) shell.openExternal(url).catch(() => {});
+  });
+
   win.webContents.on('did-finish-load', () => console.log('[main] page loaded'));
   win.webContents.on('did-fail-load', (_e, code, desc, url) =>
     console.error('[main] page FAILED to load: ' + code + ' ' + desc + ' ' + url));
@@ -2259,6 +2285,97 @@ ipcMain.handle('update:download', async (_e, url, name) => {
   });
 });
 
+/*
+ * ─────────────────────────── installing it, in place ──────────────────────
+ *
+ * An app cannot replace itself while it is running, so the swap is done by a
+ * small script that outlives us: it waits for this process to exit, moves the
+ * old bundle aside, copies the new one in, and relaunches.
+ *
+ * MOVED ASIDE, NOT DELETED. If the copy fails half way — a full disk, a bad
+ * download, the volume going away — the old app is put straight back and
+ * relaunched. The failure mode this is written against is a campus Mac with no
+ * working app and a service in an hour, which is far worse than not updating.
+ *
+ * No sudo: /Applications is admin-writable on macOS and the bundle belongs to
+ * the operator, so nothing here needs a password. If that is ever not true the
+ * copy fails, the old app comes back, and the log says so.
+ */
+ipcMain.handle('update:install', async (_e, dmgPath) => {
+  const dmg = String(dmgPath || '');
+  if (!dmg || !fs.existsSync(dmg)) return { ok: false, error: 'That installer is no longer on disk.' };
+
+  /* Never mid-service. Quitting the app stops every listener's captions, and an
+     update is never worth that — the operator stops translation first. */
+  if (engineIsLive) {
+    return { ok: false, error: 'Translation is live. Press Stop translating first, then install.' };
+  }
+
+  const appPath = app.getPath('exe').replace(/\/Contents\/MacOS\/[^/]+$/, '');
+  if (!/\.app$/.test(appPath)) {
+    return { ok: false, error: 'This copy is not running from an .app bundle, so it cannot replace itself.' };
+  }
+
+  const tmp = path.join(require('os').tmpdir(), 'ct-install-' + process.pid + '.sh');
+  const mount = '/Volumes/ChurchTranslateUpdate';
+  const aside = appPath + '.replacing-' + process.pid;
+  const script = [
+    '#!/bin/bash',
+    '# Written by Church Translate to swap itself. Safe to delete.',
+    'set -u',
+    'DMG=' + JSON.stringify(dmg),
+    'APP=' + JSON.stringify(appPath),
+    'ASIDE=' + JSON.stringify(aside),
+    'MNT=' + JSON.stringify(mount),
+    'PID=' + process.pid,
+    'LOG="$HOME/Library/Application Support/Church Translate/data/logs/install.log"',
+    'mkdir -p "$(dirname "$LOG")"',
+    'say(){ echo "$(date "+%Y-%m-%d %H:%M:%S") $*" >> "$LOG"; }',
+    'say "installing $DMG into $APP"',
+    '# wait for the app to actually be gone (up to 30s)',
+    'for i in $(seq 1 60); do kill -0 "$PID" 2>/dev/null || break; sleep 0.5; done',
+    'if kill -0 "$PID" 2>/dev/null; then say "app did not exit; aborting"; exit 1; fi',
+    'hdiutil detach "$MNT" -quiet 2>/dev/null',
+    'if ! hdiutil attach "$DMG" -nobrowse -quiet -mountpoint "$MNT"; then say "could not mount"; open -a "$APP"; exit 1; fi',
+    'NEW="$MNT/Church Translate.app"',
+    '# refuse to touch the installed app unless the replacement is really there',
+    'if [ ! -f "$NEW/Contents/Info.plist" ]; then say "disk image has no app"; hdiutil detach "$MNT" -quiet; open -a "$APP"; exit 1; fi',
+    'rm -rf "$ASIDE"',
+    'if ! mv "$APP" "$ASIDE"; then say "could not move the old app aside"; hdiutil detach "$MNT" -quiet; open -a "$APP"; exit 1; fi',
+    'if cp -R "$NEW" "$APP"; then',
+    '  xattr -dr com.apple.quarantine "$APP" 2>/dev/null',
+    '  say "installed $( /usr/libexec/PlistBuddy -c "Print :CFBundleVersion" "$APP/Contents/Info.plist" 2>/dev/null )"',
+    '  rm -rf "$ASIDE"',
+    'else',
+    '  say "copy failed — putting the old app back"',
+    '  rm -rf "$APP"; mv "$ASIDE" "$APP"',
+    'fi',
+    'hdiutil detach "$MNT" -quiet 2>/dev/null',
+    'open -a "$APP"',
+    'say "relaunched"',
+    'rm -f "$0"'
+  ].join('\n');
+
+  try {
+    fs.writeFileSync(tmp, script, { mode: 0o755 });
+  } catch (e) {
+    return { ok: false, error: 'Could not prepare the installer: ' + e.message };
+  }
+
+  /* Detached and unref'd, or it dies with us the moment we quit. */
+  try {
+    const child = spawn('/bin/bash', [tmp], { detached: true, stdio: 'ignore' });
+    child.unref();
+  } catch (e) {
+    return { ok: false, error: 'Could not start the installer: ' + e.message };
+  }
+
+  /* Give the renderer a moment to show the message before we go. */
+  forceQuit = true;
+  setTimeout(() => { try { app.quit(); } catch (_) {} }, 600);
+  return { ok: true };
+});
+
 ipcMain.handle('update:reveal', (_e, p2) => { try { shell.showItemInFolder(String(p2)); return true; } catch (_) { return false; } });
 
 ipcMain.handle('config:get', () => loadConfig());

app/package.json

@@ -2,7 +2,7 @@
   "name": "church-translate-engine",
   "productName": "Church Translate",
   "version": "3.23.2",
-  "buildNumber": 113,
+  "buildNumber": 126,
   "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": "113",
+    "buildVersion": "126",
     "win": {
       "target": [
         {

app/preload.js

@@ -24,6 +24,7 @@ contextBridge.exposeInMainWorld('engineHost', {
   updateCheck:  ()      => ipcRenderer.invoke('update:check'),
   updateDownload: (u, n) => ipcRenderer.invoke('update:download', u, n),
   updateReveal: (p)     => ipcRenderer.invoke('update:reveal', p),
+  updateInstall: (p)    => ipcRenderer.invoke('update:install', p),
   onUpdateProgress: (fn) => ipcRenderer.on('update:progress', (_e, p) => fn(p)),
   settingsExport: ()    => ipcRenderer.invoke('settings:export'),
   settingsImport: ()    => ipcRenderer.invoke('settings:import'),

app/server/public/listen.js

@@ -163,10 +163,21 @@
   function renderFeatured() {
     var wrap = $('featured');
     wrap.textContent = '';
+    /*
+     * THE OPERATOR'S LIST IS THE LIST. This used to unshift the source
+     * language in unconditionally, on the reasoning that plenty of people want
+     * the English captions for accessibility rather than translation — which
+     * is true, and still available, but it is not this code's call to make.
+     * The operator has a switch for every language including English, and for
+     * the source language alone that switch did nothing: English was put back
+     * on every render, so a desk that had deliberately turned it off still
+     * offered it as the first button on the page. A control that silently
+     * refuses is worse than no control.
+     *
+     * Wanting English captions is now one click in Settings, in the same list
+     * as every other language, and it stays where it is put.
+     */
     var list = (app.cfg.featured || []).slice();
-    /* The source language belongs in the list too — plenty of people want the
-       English captions for accessibility, not translation. */
-    if (list.indexOf(app.cfg.sourceLanguage) === -1) list.unshift(app.cfg.sourceLanguage);
     list.forEach(function (code) {
       var b = langButton(code);
       if (b) wrap.appendChild(b);
@@ -508,7 +519,16 @@
     /* After any interruption the player resumes where it left off and stays
        behind live forever — no error, no stall, just permanently late. Every
        one of these events is a chance to catch back up. */
-    ['playing', 'stalled', 'waiting', 'canplay', 'loadedmetadata'].forEach(function (ev) {
+    /*
+     * 'stalled' and 'waiting' are deliberately NOT in this list. A seek on a
+     * live HLS stream makes the element re-buffer, which raises exactly those
+     * two events — so seeking from them is a loop that feeds itself: seek,
+     * stall, seek, stall. On Safari, where HLS is played natively and a seek
+     * lands on a segment boundary, each turn of that loop replays or skips
+     * part of a sentence. That is the "it repeats a bit two or three times
+     * then moves on" reported from iPhones.
+     */
+    ['playing', 'canplay', 'loadedmetadata'].forEach(function (ev) {
       a.addEventListener(ev, function () { seekLive(); });
     });
 
@@ -588,8 +608,28 @@
    * and 4s of tolerance plus a 5s check interval meant real drift could reach
    * nine seconds before anyone looked.
    */
-  var DRIFT_MAX = 1.5;
+  /*
-  var DRIFT_LAND = 0.6;
+   * DRIFT_LAND WAS 0.6 S, AND ONE SEGMENT IS 0.697 S.
+   *
+   * So the target sat INSIDE the newest segment — a point the player very
+   * often did not have yet. It would be dragged up to the edge, run out of
+   * audio, stall, and the stall would trigger another correction. A phone
+   * cannot hold a position closer to live than the segments arriving.
+   *
+   * Three segments back (~2.1 s) is what HLS players choose for themselves on
+   * a live playlist, and it is the smallest target with enough buffered audio
+   * to survive one late segment. The tolerance is wider than one segment too,
+   * so an ordinary arrival wobble is not read as drift.
+   *
+   * It costs about a second and a half of extra delay. A listener a second
+   * further behind is following the service; a listener whose audio keeps
+   * jumping backwards is not.
+   */
+  var DRIFT_MAX = 3.0;
+  var DRIFT_LAND = 2.1;
+  /* A correction needs time to settle before its own result is judged. */
+  var SEEK_COOLDOWN_MS = 5000;
+  var lastSeekAt = 0;
 
   /*
    * How far behind the live edge this listener is SUPPOSED to be.
@@ -616,6 +656,11 @@
       var want = driftTarget();
       var behind = (edge - a.currentTime) - want;   // + = too late, - = too early
       if (!force && Math.abs(behind) <= DRIFT_MAX) return;
+      /* One correction at a time. Without this, timeupdate (four times a
+         second) can fire a fresh seek while the last one is still buffering,
+         and the element never gets a chance to settle anywhere. */
+      if (!force && Date.now() - lastSeekAt < SEEK_COOLDOWN_MS) return;
+      lastSeekAt = Date.now();
       /*
        * Land just BEHIND the target, never on the edge. Seeking exactly to the
        * live edge leaves no buffered audio at all, so the phone stalls on the

app/server/server.js

@@ -500,16 +500,57 @@ const ENGINE_STALE_MS = 12000;
  * with one plain sentence does. Computed here so every operator surface —
  * in-app pane, browser page — shows the same verdict.
  */
+/*
+ * WHEN IT IS BEHIND, SAY WHAT IS LOADING IT.
+ *
+ * Translation cost is roughly linear in the number of active languages, through
+ * ONE NLLB process — measured, five languages in 1.9 s. So the single most
+ * useful fact about a machine that is falling behind is how many languages it
+ * is carrying, and that number was computed one function away and never shown.
+ * A campus reported "constantly behind, in the red" and the cause took an
+ * afternoon to find; it was eight languages on hardware tuned against one.
+ */
+/* How long a stumble keeps colouring the verdict. Long enough that a real
+   problem stays visible while someone walks to the desk, short enough that a
+   one-off does not outlive the sentence after it. */
+const TROUBLE_WINDOW_MS = 120000;
+
+function loadNote() {
+  const n = activeLanguages().length;
+  if (n < 2) return '';
+  return ' Carrying ' + n + ' languages' +
+         (config.allowAllLanguages ? ', and listeners may add more' : '') + '.';
+}
+
 function healthVerdict(connected, stale) {
   const es = state.engineStatus || {};
   if (!connected)               return { level: 'red',   detail: 'The translation app is not connected.' };
   if (stale)                    return { level: 'red',   detail: 'The translation app has stopped responding.' };
   if (!state.live)              return { level: 'green', detail: 'Ready.' };
   if (!es.modelsReady)          return { level: 'amber', detail: 'Models are still loading.' };
-  if ((es.lagMs || 0) > 12000 || (es.captionOnlyFinals || 0) > 0)
+  /*
-    return { level: 'red',   detail: 'Falling badly behind — some sentences are captions only.' };
+   * RECENTLY, not ever.
-  if ((es.lagMs || 0) > 6000 || (es.queue || 0) >= 2 || (es.degradedFinals || 0) > 0)
+   *
-    return { level: 'amber', detail: 'Running behind — idle languages may be trimmed to catch up.' };
+   * captionOnlyFinals is a running total for the whole service, and testing it
+   * for "more than zero" meant a single stale sentence pinned the desk's light
+   * red until the next restart. MEASURED: a campus Mac took one 16 s stall at
+   * 14:25 — caused by two Screen Sharing sessions competing for the machine —
+   * recovered immediately to a 421 ms lag with an empty queue, and still showed
+   * red half an hour later. An operator who looks up and sees red wants to know
+   * what is wrong NOW; a light that cannot go back to green teaches them to
+   * ignore it.
+   *
+   * So the totals still travel, for the record and for the operator page, but
+   * the verdict asks when it last happened.
+   */
+  const recentCaptionOnly = es.captionOnlyAt && (Date.now() - es.captionOnlyAt) < TROUBLE_WINDOW_MS;
+  if ((es.lagMs || 0) > 12000 || recentCaptionOnly)
+    return { level: 'red',
+             detail: 'Falling badly behind — some sentences are captions only.' + loadNote() };
+  const recentDegraded = es.degradedAt && (Date.now() - es.degradedAt) < TROUBLE_WINDOW_MS;
+  if ((es.lagMs || 0) > 6000 || (es.queue || 0) >= 2 || recentDegraded)
+    return { level: 'amber',
+             detail: 'Running behind — idle languages may be trimmed to catch up.' + loadNote() };
   if (es.cloud && es.cloud.parked)
     return { level: 'amber', detail: 'Natural voices are down — the built-in voices have taken over.' };
   /* A fallback in the last minute means one language just changed voice
@@ -1076,7 +1117,22 @@ const server = http.createServer(async (req, res) => {
   }
   if (req.method === 'OPTIONS') { res.writeHead(origin ? 204 : 405).end(); return; }
 
-  if (p === '/healthz') { sendJSON(res, 200, { ok: true, live: state.live, build: BUILD }); return; }
+  /*
+   * The APP's version, plainly, to anyone who can reach this port.
+   *
+   * `build` here has always been a hash of the listener-page assets — a
+   * cache-busting token, not a version — so the only way to tell what a campus
+   * Mac was running was to install something and watch the hash move. With an
+   * updater in the field that is the first question anyone asks, so answer it.
+   */
+  if (p === '/healthz') {
+    sendJSON(res, 200, {
+      ok: true, live: state.live, build: BUILD,
+      version: process.env.CT_APP_VERSION || '',
+      appBuild: process.env.CT_APP_BUILD || ''
+    });
+    return;
+  }
 
   // --- Companion / Stream Deck control -------------------------------
   //  GET or POST, token in ?key= or the X-Control-Token header.

docs/PUBLIC-ACCESS.md

@@ -57,16 +57,45 @@ For a second campus, repeat with its own name — `translate-north`,
 
 ---
 
-## The other way: your existing nginx proxy
+## The other way: a name on your existing reverse proxy
 
-You already run a reverse proxy at `10.1.1.4` fronting `check.watersmedia.org`,
+You already run a reverse proxy on the NAS at `10.1.1.4` (Boba-Fett, Synology
-with split-horizon DNS. It can front this too, though it means the traffic goes
+DSM) fronting `check.watersmedia.org`. It can front this too, though it means
-through the NAS network to reach the booth Mac.
+the traffic goes through the NAS network to reach the booth Mac.
 
-Add a DNS record for `translate.watersmedia.org` — public to your WAN address,
+This is what North Attleboro runs as of 2026-10-15, in the **LAN-only** form:
-internal to `10.1.1.4` — and a server block. Copy the one that already serves
+`http://translate.watersmedia.org` works on the building's WiFi at both the
-the checklist app, change the name, and point it at the **booth Mac**, not the
+Apollo Beach and North Attleboro sites and nowhere else. Nothing was opened to
-NAS:
+the WAN. The pieces, with the exact scripts and a step-by-step runbook under
+[`examples/waters-church-na/`](examples/waters-church-na/README.md):
+
+| Piece | Where | What |
+| --- | --- | --- |
+| Local DNS | UniFi consoles at AB and NA (Settings → Policy Table → DNS) | A record `translate.watersmedia.org` → `10.1.1.4`, TTL 300, created with `unifi-dns-record.py` and a per-console Network API key |
+| Proxy rule | DSM → Control Panel → Login Portal → Advanced → Reverse Proxy | HTTP `translate.watersmedia.org:80` → HTTP `10.1.7.39:3100`, WebSocket headers, `X-Forwarded-Host: $http_host`, read timeout 3600 s |
+| HTTPS | `/usr/local/etc/nginx/sites-enabled/translate-redirect.conf` on the NAS | `https://` answers a 301 to `http://`; the name has no certificate, so browsers warn before the redirect |
+
+Both NAS pieces come from `boba-fett-translate-proxy.sh`, run as
+`ssh -t boba-fett sudo bash translate-proxy.sh` because DSM's reverse-proxy API
+is root-only. Going through DSM rather than a hand-edited nginx file means the
+rule shows up in the DSM UI and survives DSM updates. DSM adds `Host`,
+`X-Real-IP`, `X-Forwarded-For` and `X-Forwarded-Proto` on its own.
+
+Then: Operator page → **Public address** → `http://translate.watersmedia.org`
+(no trailing slash), so the QR code and poster use the name instead of the
+IP and port.
+
+To let people off-site use the same name later: add a public DNS record for
+`translate.watersmedia.org` pointing at the NA WAN address, get a certificate
+in DSM (Control Panel → Security → Certificate → Let's Encrypt), replace the
+redirect with an HTTPS rule to the same destination, and switch Public address
+to `https://`. The app behaves the same either way, including the `/operator`
+404 through a proxy.
+
+### If the proxy is plain nginx instead of DSM
+
+DSM writes most of this for you. On a hand-managed nginx the server block
+needs all of it:
 
 ```nginx
 server {
@@ -77,7 +106,7 @@ server {
     ssl_certificate_key /path/to/privkey.pem;
 
     location / {
-        proxy_pass http://10.6.3.222:3100;      # the booth Mac
+        proxy_pass http://10.1.7.39:3100;      # the booth Mac
 
         proxy_set_header Host              $host;
         proxy_set_header X-Real-IP         $remote_addr;
@@ -95,21 +124,36 @@ server {
         # the room reconnects at once.
         proxy_read_timeout  3600s;
         proxy_send_timeout  3600s;
+
+        # Live audio: do not hold HLS segments back.
+        proxy_buffering off;
     }
 }
 ```
 
-This has one real drawback the tunnel does not: the booth Mac needs a fixed
+Either way the booth Mac needs a fixed address or a DHCP reservation, or the
-address on the network, or the proxy breaks the next time DHCP moves it.
+proxy breaks the next time DHCP moves it.
 
 ---
 
 ## Checking it worked
 
 ```bash
-curl -s https://translate.watersmedia.org/healthz
+curl -s http://translate.watersmedia.org/healthz      # https:// once published
 ```
 
-Should return `{"ok":true,…}`. Then open the page on a phone **with WiFi turned
+Should return `{"ok":true,…}`, the same as `curl -s http://10.1.7.39:3100/healthz`.
-off** — that is the real test. If the page loads but captions never appear, the
+A proxy that passes the WebSocket answers `HTTP/1.1 101 Switching Protocols` to:
-WebSocket headers are missing.
+
+```bash
+curl -si -N -H 'Connection: Upgrade' -H 'Upgrade: websocket' \
+  -H 'Sec-WebSocket-Version: 13' -H 'Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==' \
+  http://translate.watersmedia.org/ws | head -1
+```
+
+Then open the page on a phone: for the LAN-only setup on the guest WiFi, for a
+published one **with WiFi turned off**. That is the real test. If the page loads
+but captions never appear, the WebSocket headers are missing. If phones on
+guest WiFi cannot connect at all, look at client isolation on that network
+before anything else. `/operator` returning 404 through the proxy is by design;
+staff use `http://10.1.7.39:3100/operator` on the LAN.

docs/examples/waters-church-na/README.md

@@ -0,0 +1,93 @@
+# translate.watersmedia.org — local DNS and reverse proxy
+
+Puts the Church Translate congregation page on a church hostname inside the
+Apollo Beach and North Attleboro networks. LAN only, plain HTTP, no WAN access.
+The app's own requirements are in [PUBLIC-ACCESS.md](../../PUBLIC-ACCESS.md). This
+was done on 2026-10-15 against app 3.23.2 build 121.
+
+| What | Value |
+| --- | --- |
+| App host | Translate Mac, North Attleboro LAN `10.1.7.39` |
+| App port | TCP 3100, plain HTTP + WebSocket on `/ws` (the only port to expose) |
+| Reverse proxy | Boba-Fett (Synology DSM 7.0.1), `10.1.1.4`, `ssh boba-fett` (port 202, user Michael) |
+| Hostname | `translate.watersmedia.org` |
+| Local DNS | A record on the AB and NA UDM Pro consoles → `10.1.1.4`, TTL 300 |
+| HTTPS | no certificate; `https://translate.watersmedia.org` answers 301 to `http://` |
+
+`curl -s http://10.1.7.39:3100/healthz` should return `{"ok":true,"live":true,...}`
+before anything below is tested.
+
+## 1. Local DNS on UniFi (AB and NA) — done 2026-10-15
+
+Each console has its own Network API key saved as
+`~/.config/unifi/<site>-network-api-key` (created in Settings → Control Plane →
+Integrations → Create API Key; all five sites are saved on Michael's Mac). The
+record was created with:
+
+```bash
+python3 docs/examples/waters-church-na/unifi-dns-record.py translate.watersmedia.org 10.1.1.4 --sites apollo-beach,north-attleboro
+```
+
+Resulting policy ids: AB `379f868d-a956-4ec1-acef-13557153ff3f`, NA
+`16bf7109-ec68-41f9-9c16-fa6a62471430`. Both gateways answer `10.1.1.4`.
+`--list` shows every DNS policy per console; `--dry-run` previews.
+
+Why Boba-Fett and not the Mac: the proxy owns the hostname so the port never
+appears in the URL, and AB clients reach `10.1.1.4` over the site-to-site link
+exactly as they already do for `chronicles-na.waterschurch.org`.
+
+## 2. Reverse proxy on Boba-Fett — done 2026-10-15
+
+[boba-fett-translate-proxy.sh](boba-fett-translate-proxy.sh) does the whole
+job and is idempotent. It was run on 2026-10-15; afterwards `/healthz`,
+`/api/languages`, the `/ws` upgrade (101) and the HTTPS 301 all checked out
+from both the AB and NA LANs, and `/operator` returned 404 as designed. A copy lives at `~/translate-proxy.sh` on Boba-Fett
+(Michael's home). DSM's reverse-proxy API and nginx reload both need root, and
+sudo there asks for Michael's password, so run it interactively:
+
+```bash
+ssh -t boba-fett sudo bash translate-proxy.sh
+```
+
+What it creates:
+
+| Piece | Where | Content |
+| --- | --- | --- |
+| DSM reverse proxy rule | Control Panel → Login Portal → Advanced → Reverse Proxy, "translate.watersmedia.org" | HTTP `translate.watersmedia.org:80` → HTTP `10.1.7.39:3100`; custom headers `Upgrade: $http_upgrade`, `Connection: $connection_upgrade` (WebSocket), `X-Forwarded-Host: $http_host`; read timeout 3600 s; HTTP/1.1 |
+| HTTPS redirect | `/usr/local/etc/nginx/sites-enabled/translate-redirect.conf` | `server { listen 443 ssl; server_name translate.watersmedia.org; return 301 http://translate.watersmedia.org$request_uri; }` |
+
+DSM already sends `Host`, `X-Real-IP`, `X-Forwarded-For` and
+`X-Forwarded-Proto` on every rule. The whole host lands on `/`, which the app
+requires. `/operator` returning 404 through the proxy is intended; staff use
+`http://10.1.7.39:3100/operator` on the LAN.
+
+To undo: delete the rule in the DSM Reverse Proxy list, remove the redirect
+file, and `sudo synosystemctl reload nginx`.
+
+Known limits:
+
+- The HTTPS redirect only runs after a TLS handshake with Boba-Fett's default
+  certificate, so a browser shows a certificate warning first. A trusted
+  certificate for this name would need DNS-01 validation against the
+  watersmedia.org zone (cPanel), which is not set up.
+- DSM's reverse proxy cannot turn `proxy_buffering` off. HLS segments under
+  `/live/` are small discrete files and the WebSocket is a tunnel after upgrade,
+  so the effect is minor; if audio lag is reported, that is the first thing to
+  revisit with a hand-written nginx include.
+
+## 3. After the proxy answers
+
+1. On the NA LAN open `http://10.1.7.39:3100/operator`, enter the operator PIN,
+   and set **Public address** to `http://translate.watersmedia.org` (no trailing
+   slash). Otherwise the QR code and poster keep advertising `10.1.7.39:3100`.
+2. Verify from a machine at AB and one at NA:
+
+```bash
+curl -s http://translate.watersmedia.org/healthz
+```
+
+   It must return the same JSON as the direct `10.1.7.39:3100` check.
+3. Open the page on a phone on guest wifi and confirm captions appear
+   (WebSocket) and spoken audio plays (`/live/`). If phones cannot connect at
+   all, look at client isolation on the guest network and the guest → `10.1.1.4`
+   firewall rule before anything else.

docs/examples/waters-church-na/boba-fett-translate-proxy.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+# translate.watersmedia.org on Boba-Fett (Synology DSM 7.0.1).
+#
+# 1. Creates the DSM reverse-proxy rule  http://translate.watersmedia.org:80
+#    -> http://10.1.7.39:3100 (Church Translate) with WebSocket headers,
+#    X-Forwarded-Host, and a 3600 s read timeout, through DSM's own API so it
+#    shows up in Control Panel -> Login Portal -> Advanced -> Reverse Proxy.
+# 2. Adds an nginx server block that answers https://translate.watersmedia.org
+#    with a 301 to the http:// address (the name is LAN-only and has no
+#    certificate, so browsers warn before the redirect; that is expected).
+# 3. Tests the nginx config, reloads it, and prints a local check.
+#
+# Idempotent: re-running skips the rule if it exists and rewrites the redirect.
+# Run on Boba-Fett as root:   sudo bash ~/translate-proxy.sh
+set -euo pipefail
+
+NAME=translate.watersmedia.org
+BACKEND_IP=10.1.7.39
+BACKEND_PORT=3100
+RP_JSON=/usr/syno/etc/www/ReverseProxy.json
+REDIRECT_CONF=/usr/local/etc/nginx/sites-enabled/translate-redirect.conf
+
+if [ "$(id -u)" != 0 ]; then
+  echo "Run with sudo: sudo bash $0" >&2
+  exit 1
+fi
+
+echo "== 1. DSM reverse proxy rule for $NAME"
+if grep -q "\"fqdn\" : \"$NAME\"" "$RP_JSON"; then
+  echo "   rule already present in $RP_JSON, skipping create"
+else
+  # $http_upgrade etc. are nginx variables and must reach DSM literally.
+  ENTRY='{"description":"translate.watersmedia.org","frontend":{"acl":null,"fqdn":"translate.watersmedia.org","https":{"hsts":false},"port":80,"protocol":0},"backend":{"fqdn":"10.1.7.39","port":3100,"protocol":0},"customize_headers":[{"name":"Upgrade","value":"$http_upgrade"},{"name":"Connection","value":"$connection_upgrade"},{"name":"X-Forwarded-Host","value":"$http_host"}],"proxy_connect_timeout":60,"proxy_read_timeout":3600,"proxy_send_timeout":60,"proxy_http_version":1,"proxy_intercept_errors":false}'
+  OUT=$(/usr/syno/bin/synowebapi --exec api=SYNO.Core.AppPortal.ReverseProxy method=create version=1 entry="$ENTRY" 2>&1 || true)
+  echo "   $OUT"
+  if ! echo "$OUT" | grep -q '"success" *: *true'; then
+    echo "   synowebapi did not report success; stopping before the redirect." >&2
+    exit 1
+  fi
+fi
+
+echo "== 2. HTTPS -> HTTP redirect block"
+cat > "$REDIRECT_CONF" <<'EOF'
+# translate.watersmedia.org is served over plain HTTP on the LAN (no certificate).
+# Anyone who types https:// is sent to the http:// address. Added 2026-10-15.
+server {
+    listen 443 ssl;
+    server_name translate.watersmedia.org;
+    return 301 http://translate.watersmedia.org$request_uri;
+}
+EOF
+echo "   wrote $REDIRECT_CONF"
+
+echo "== 3. nginx test + reload"
+/usr/bin/nginx -t
+/usr/syno/bin/synosystemctl reload nginx 2>/dev/null || /usr/bin/nginx -s reload
+echo "   reloaded"
+
+echo "== 4. Local checks from Boba-Fett"
+echo -n "   http  /healthz : "
+curl -s -m 5 --resolve "$NAME:80:127.0.0.1" "http://$NAME/healthz"; echo
+echo -n "   https /        : "
+curl -sk -m 5 -o /dev/null -w '%{http_code} -> %{redirect_url}\n' --resolve "$NAME:443:127.0.0.1" "https://$NAME/"
+echo "done"

docs/examples/waters-church-na/unifi-dns-record.py

@@ -0,0 +1,211 @@
+#!/usr/bin/env python3
+"""Create or update a local DNS A record on every Waters Church UniFi console.
+
+Usage:
+    docs/examples/waters-church-na/unifi-dns-record.py repo.watersmedia.org 10.3.8.90
+    docs/examples/waters-church-na/unifi-dns-record.py repo.watersmedia.org 10.3.8.90 --sites apollo-beach,norwood
+    docs/examples/waters-church-na/unifi-dns-record.py repo.watersmedia.org 10.3.8.90 --dry-run
+    docs/examples/waters-church-na/unifi-dns-record.py --list                # show every DNS policy per site
+
+Each console needs its own Network API key (Site Manager keys from api.ui.com are
+rejected locally). Create one per console in the UniFi UI:
+    Settings -> Control Plane -> Integrations -> Create API Key
+and save it, one line, mode 600, as:
+    ~/.config/unifi/<site>-network-api-key
+where <site> is one of the names in SITES below.
+
+The script talks to the console's Network Integration API
+(/proxy/network/integration/v1/sites/{siteId}/dns/policies) over the LAN /
+site-to-site links, so it must run from inside the church network. Gateways use
+self-signed certificates, so certificate verification is disabled for them.
+Keys are read from disk and sent only in the X-API-KEY header; they are never
+printed.
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import os
+import shutil
+import ssl
+import subprocess
+import sys
+import urllib.error
+import urllib.parse
+import urllib.request
+
+# Console name -> gateway LAN address (UDM Pro at each site, 2026-10).
+SITES = {
+    "apollo-beach": "10.3.0.1",
+    "north-attleboro": "10.1.0.1",
+    "woonsocket": "10.2.0.1",
+    "norwood": "10.4.0.1",
+    "southcoast": "10.5.0.1",
+}
+
+KEY_DIR = os.path.expanduser("~/.config/unifi")
+TIMEOUT = 15
+
+
+class ApiError(RuntimeError):
+    pass
+
+
+class Console:
+    def __init__(self, name: str, gateway: str):
+        self.name = name
+        self.gateway = gateway
+        self.base = f"https://{gateway}/proxy/network/integration/v1"
+        self.key_path = os.path.join(KEY_DIR, f"{name}-network-api-key")
+        self.key = self._load_key()
+        self.ctx = ssl.create_default_context()
+        self.ctx.check_hostname = False
+        self.ctx.verify_mode = ssl.CERT_NONE
+
+    def _load_key(self) -> str | None:
+        try:
+            with open(self.key_path) as fh:
+                key = fh.read().strip()
+        except FileNotFoundError:
+            return None
+        return key or None
+
+    def request(self, method: str, path: str, body: dict | None = None, query: dict | None = None):
+        url = self.base + path
+        if query:
+            url += "?" + urllib.parse.urlencode(query)
+        data = json.dumps(body).encode() if body is not None else None
+        req = urllib.request.Request(url, data=data, method=method)
+        req.add_header("X-API-KEY", self.key or "")
+        req.add_header("Accept", "application/json")
+        if data is not None:
+            req.add_header("Content-Type", "application/json")
+        try:
+            with urllib.request.urlopen(req, timeout=TIMEOUT, context=self.ctx) as resp:
+                raw = resp.read()
+                return json.loads(raw) if raw else None
+        except urllib.error.HTTPError as e:
+            detail = e.read().decode(errors="replace")[:300]
+            raise ApiError(f"{method} {path} -> HTTP {e.code}: {detail}") from None
+        except (urllib.error.URLError, TimeoutError, OSError) as e:
+            raise ApiError(f"{method} {path} -> {e}") from None
+
+    def site_id(self) -> str:
+        sites = self.request("GET", "/sites").get("data", [])
+        if not sites:
+            raise ApiError("console reports no sites")
+        for s in sites:
+            if s.get("internalReference") == "default" or s.get("name") == "default":
+                return s["id"]
+        return sites[0]["id"]
+
+    def dns_policies(self, site_id: str) -> list[dict]:
+        out: list[dict] = []
+        offset, limit = 0, 100
+        while True:
+            page = self.request("GET", f"/sites/{site_id}/dns/policies", query={"offset": offset, "limit": limit})
+            data = page.get("data", [])
+            out.extend(data)
+            total = page.get("totalCount")
+            offset += len(data)
+            if not data or (total is not None and offset >= total) or len(data) < limit:
+                return out
+
+    def ensure_a_record(self, site_id: str, fqdn: str, ipv4: str, ttl: int | None, dry_run: bool) -> str:
+        existing = [p for p in self.dns_policies(site_id) if p.get("domain", "").lower() == fqdn.lower()]
+        a_records = [p for p in existing if p.get("type") == "A_RECORD"]
+        other = [p for p in existing if p.get("type") != "A_RECORD"]
+        if other:
+            kinds = ", ".join(sorted({p.get("type", "?") for p in other}))
+            return f"SKIPPED: {fqdn} already has a non-A policy here ({kinds}); fix by hand"
+        if len(a_records) > 1:
+            return f"SKIPPED: {len(a_records)} A records already exist for {fqdn}; fix by hand"
+
+        body = {"type": "A_RECORD", "enabled": True, "domain": fqdn, "ipv4Address": ipv4}
+        if ttl:
+            body["ttlSeconds"] = ttl
+
+        if a_records:
+            cur = a_records[0]
+            same = cur.get("ipv4Address") == ipv4 and cur.get("enabled", True) and (ttl is None or cur.get("ttlSeconds") == ttl)
+            if same:
+                return f"unchanged: {fqdn} -> {ipv4} already present (id {cur.get('id')})"
+            if dry_run:
+                return f"would UPDATE {fqdn}: {cur.get('ipv4Address')} -> {ipv4} (id {cur.get('id')})"
+            self.request("PUT", f"/sites/{site_id}/dns/policies/{cur['id']}", body=body)
+            return f"UPDATED {fqdn}: {cur.get('ipv4Address')} -> {ipv4}"
+
+        if dry_run:
+            return f"would CREATE {fqdn} -> {ipv4}"
+        created = self.request("POST", f"/sites/{site_id}/dns/policies", body=body)
+        return f"CREATED {fqdn} -> {ipv4} (id {created.get('id') if isinstance(created, dict) else '?'})"
+
+
+def resolve_via(gateway: str, fqdn: str) -> str:
+    """Ask the gateway's resolver directly; returns the answer or a short status."""
+    dig = shutil.which("dig")
+    if not dig:
+        return "(dig not installed)"
+    try:
+        res = subprocess.run([dig, "+short", "+time=3", "+tries=1", f"@{gateway}", fqdn, "A"],
+                             capture_output=True, text=True, timeout=10)
+    except subprocess.TimeoutExpired:
+        return "(timeout)"
+    answer = res.stdout.strip().replace("\n", " ")
+    return answer or "(no answer)"
+
+
+def main() -> int:
+    ap = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
+    ap.add_argument("fqdn", nargs="?", help="host name, e.g. repo.watersmedia.org")
+    ap.add_argument("ipv4", nargs="?", help="IPv4 address the name should resolve to")
+    ap.add_argument("--sites", default=",".join(SITES), help="comma-separated subset of: " + ", ".join(SITES))
+    ap.add_argument("--ttl", type=int, default=300, help="TTL in seconds (default 300; the API rejects a null TTL)")
+    ap.add_argument("--dry-run", action="store_true", help="show what would change without writing")
+    ap.add_argument("--list", action="store_true", help="print every DNS policy on each console and exit")
+    ap.add_argument("--no-verify", action="store_true", help="skip the dig check after writing")
+    args = ap.parse_args()
+
+    if not args.list and (not args.fqdn or not args.ipv4):
+        ap.error("fqdn and ipv4 are required unless --list is given")
+
+    names = [s.strip() for s in args.sites.split(",") if s.strip()]
+    unknown = [n for n in names if n not in SITES]
+    if unknown:
+        ap.error(f"unknown site(s): {', '.join(unknown)}")
+
+    failures = 0
+    for name in names:
+        console = Console(name, SITES[name])
+        label = f"{name:16s} {console.gateway:10s}"
+        if not console.key:
+            print(f"{label} NO KEY: save the console's API key to {console.key_path}")
+            failures += 1
+            continue
+        try:
+            site_id = console.site_id()
+            if args.list:
+                policies = console.dns_policies(site_id)
+                print(f"{label} {len(policies)} DNS policies")
+                for p in sorted(policies, key=lambda p: p.get("domain", "")):
+                    target = p.get("ipv4Address") or p.get("ipv6Address") or p.get("targetDomain") or p.get("text") or ""
+                    flag = "" if p.get("enabled", True) else " (disabled)"
+                    print(f"    {p.get('type', '?'):12s} {p.get('domain', ''):40s} -> {target}{flag}")
+                continue
+            result = console.ensure_a_record(site_id, args.fqdn, args.ipv4, args.ttl, args.dry_run)
+            line = f"{label} {result}"
+            if not args.dry_run and not args.no_verify and not result.startswith("SKIPPED"):
+                line += f" | dig @{console.gateway}: {resolve_via(console.gateway, args.fqdn)}"
+            print(line)
+            if result.startswith("SKIPPED"):
+                failures += 1
+        except ApiError as e:
+            print(f"{label} FAILED: {e}")
+            failures += 1
+
+    return 1 if failures else 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())