Sound was dead in the app because status 0 is not a failure; and back is a swipe to the RIGHT

Oliver on the first shell build: *"I don't hear any of the games sounds.. daniel the umpire is
synthesized which is horrible and no music is playing on start"* — two independent causes.

- **Opaque fetch.** Capacitor serves the bundle through a custom WKURLSchemeHandler, and `fetch`
  reports those responses as `status: 0, ok: false` with the whole body present and decoding
  perfectly. All three loads in `audio.js` guarded with `if (!r.ok) throw`, so inside the app every
  recorded sound failed at the door: the umpire fell through to the synthesized `say()`, no bed
  started, no sample played. The synthesized sfx kept working, which made it read as a mixing bug
  rather than a loader one. Fixed once, in the shared `bytes()` helper every audio fetch now routes
  through — a status of 0 is the ABSENCE of an HTTP status, so trust it only when there is one and
  a real 404 still falls back. Any future `!r.ok` on a bundle-relative fetch is this same bug.
- **The ring switch.** WKWebView's WebAudio runs in the SoloAmbient session, which the hardware
  silent switch mutes outright — a silent game on a phone that lives on silent, with nothing on
  screen to explain it. AppDelegate now sets AVAudioSession `.playback`, the games category.

Confirmed in the shell: the bed reaches PLAYING, the context is `running` with no gesture at all
(autoplay really is allowed in WKWebView, as LATER predicted), and `say()` never fires. On the web,
a genuinely missing file still falls back — checked both.

And the swipe flips: **right goes back**, the way iOS's own pop gesture goes (*"that's the iOS
way"*). Left now does nothing. Noted in PROJECT.md that on a platform gesture the platform's
convention beats the literal wording of the brief, and that is worth saying up front.

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

src/audio.js

@@ -7,6 +7,20 @@ export const audio = () => {
   return AC;
 };
 
+// EVERY audio file is fetched through here, and the reason is one line of it. Inside the Capacitor
+// shell the bundle is served by a custom WKURLSchemeHandler, and `fetch` reports those responses as
+// OPAQUE: `status` 0 and `ok` false, even though the bytes are all present and decode perfectly.
+// The old guard was a plain `if (!r.ok) throw` — so in the app EVERY recorded sound failed at the
+// door: the umpire fell through to the synthesized speech fallback, no bed ever started, and not a
+// single sample played, while the synthesized sfx kept working and made it look like a mixing bug
+// (Oliver, 2026-08-20, on the first shell build: *"daniel the umpire is synthesized which is
+// horrible and no music is playing on start"*). A status of 0 is not a failure, it is the absence
+// of an HTTP status — so trust the status only when there IS one, and let a real 404 still throw.
+const bytes = url => fetch(url).then(r => {
+  if (r.status && !r.ok) throw new Error(url + ' ' + r.status);
+  return r.arrayBuffer();
+});
+
 // Umpire lines are pre-recorded files (assets/audio/*.m4a) played via WebAudio —
 // works on mobile where speechSynthesis is unreliable. say() remains the fallback.
 const VOICE = {};
@@ -48,8 +62,7 @@ export function voice(name, delay = 0, rate = 1) {
 
 function loadVoice(name) {
   if (VOICE[name]) return Promise.resolve(VOICE[name]);
-  return fetch('assets/audio/' + name + '.m4a')
-    .then(r => { if (!r.ok) throw 0; return r.arrayBuffer(); })
+  return bytes('assets/audio/' + name + '.m4a')
     .then(ab => audio().decodeAudioData(ab))
     .then(buf => (VOICE[name] = buf));
 }
@@ -119,8 +132,7 @@ export function sfx(name, vol = 1, opts = {}) {
   };
   if (SFX[name]) return play(SFX[name]);
   // a name with an extension is used as-is (weapon-click2.mp3); bare names keep the .wav default
-  fetch('assets/audio/' + (name.includes('.') ? name : name + '.wav'))
-    .then(r => { if (!r.ok) throw 0; return r.arrayBuffer(); })
+  bytes('assets/audio/' + (name.includes('.') ? name : name + '.wav'))
     .then(ab => ac.decodeAudioData(ab))
     .then(buf => { SFX[name] = buf; play(buf); })
     .catch(() => {}); // missing sample = silence, never a thrown error mid-rally
@@ -141,8 +153,7 @@ function loopBed(file, lowcut, vol, loopEnd = 0) {
   const ac = audio();
   if (beds.has(file)) return;
   beds.set(file, null);
-  fetch('assets/audio/' + file) // full filename: the beds are a mix of .wav and .m4a, see below
-    .then(r => { if (!r.ok) throw 0; return r.arrayBuffer(); })
+  bytes('assets/audio/' + file) // full filename: the beds are a mix of .wav and .m4a, see below
     .then(ab => ac.decodeAudioData(ab))
     .then(buf => {
       // RESUME AGAIN, HERE. The gesture that unlocked the context is long gone by now: the menu

src/main.js

@@ -537,7 +537,8 @@ document.getElementById('sBack').addEventListener('click', () => {
 });
 document.getElementById('bsBack').addEventListener('click', () => go('secret'));
 
-// SWIPE TO GO BACK. Every screen but the splash wears exactly one chevron in its header (.hdr in
+// SWIPE TO GO BACK — RIGHTWARD, the way iOS's own pop gesture goes (Oliver, 2026-08-20: *"that's
+// the iOS way"*). Every screen but the splash wears exactly one chevron in its header (.hdr in
 // index.html) and that button ALREADY knows where back is for its own screen — the wizard's shape
 // lives in the handlers above and nowhere else. So the gesture finds the one visible chevron and
 // clicks it, rather than keeping a second map that would drift the first time a stage is added.
@@ -553,8 +554,8 @@ intro.addEventListener('touchend', e => {
   if (!from || e.touches.length) return;
   const t = e.changedTouches[0];
   const dx = t.clientX - from.x, dy = t.clientY - from.y;
-  // leftward, and clearly horizontal: the stats and board screens scroll vertically under the finger
-  if (dx > -SWIPE_MIN || Math.abs(dy) > Math.abs(dx) * 0.7) return;
+  // rightward, and clearly horizontal: the stats and board screens scroll vertically under the finger
+  if (dx < SWIPE_MIN || Math.abs(dy) > Math.abs(dx) * 0.7) return;
   const back = [...intro.querySelectorAll('.chev')].find(b => b.offsetParent); // the one on screen
   if (!back) return;
   // NOT passive, and this is why: a swipe that starts and ends inside one of the big poster cards