add sessions/0022/SESSION-0022.0-TRANSCRIPT-2026-06-26T08-40--2026-06-26T08-50.md + replace placeholder/variant SESSION-0022.0-TRANSCRIPT-2026-06-26T08-40--INPROGRESS.md

Removes the tap-to-start wall (Loading Universe splash instead), fixes audio still
silent on real Safari (single <audio> played synchronously in the toggle gesture),
both toggles default off, first Video-on couples Audio. Verified Chromium + WebKit.
290 tests + 5 Playwright E2E pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

sessions/0021/SESSION-0021.0-TRANSCRIPT-2026-06-26T08-12--2026-06-26T08-20.md

@@ -0,0 +1,88 @@
+# Session 0021.0 — Transcript
+
+> App: human-experience-filter-art
+> Start: 2026-06-26T08-12 (PST)
+> End: 2026-06-26T08-20 (PST)
+> Type: executing-plans (operator-driven hotfix/revision of session 0020's audio feature)
+> Posture: yolo
+> Claude-Session: e0cc053a-41fa-416d-a4f5-493f14984e75
+> Status: FINALIZED
+
+## Launch prompt
+
+> Show video unchecked doesn't turn off the video. Make "show video" just "Video"
+> and have a toggle like "Dev Mode" has. I can't hear any audio when "soundtrack
+> (follows altitude)" is selected. Let's just have Audio as off/on like Video for
+> now and get rid of white noise.
+
+## Pre-state
+
+- Session 0020 had just merged the audio feature to `main` (Visual×Audio split,
+  per-altitude soundtracks, pink white-noise, A/B crossfade). The operator tested it
+  live and reported three issues.
+
+## Session arc
+
+1. **Diagnosis (the key work).** Both reported bugs were reproduced *only* in the
+   operator's real browser — neither appeared in headless Chromium **or** WebKit
+   (installed `playwright install webkit` to test Safari's engine). Root causes:
+   - **Video-off doesn't blank:** `#vid` (`<video>`) and `#paint` (WebGL `<canvas>`)
+     are GPU-composited layers; the `#black` cover had *auto* z-index, so on a real
+     GPU (Safari/Chrome) the video layer can composite *above* it despite DOM order.
+     Headless software-raster hides this.
+   - **No soundtrack audio:** real Safari/iOS unlocks an `<audio>` element only when
+     `play()` is called *synchronously inside* the user gesture; the 0020 gesture
+     played in an async continuation (after `await fetch`), which Chrome allows but
+     Safari blocks. Headless WebKit relaxes autoplay, so it passed.
+   This is the session's main lesson: **Playwright headless relaxes both GPU
+   compositing and autoplay**, so the 0020 E2E couldn't have caught either — real
+   device / by-eye review is required.
+2. **Fixes (branch `session-0021`):**
+   - **Video** + **Audio** are now Dev-Mode-style on/off toggles (`.dev-switch`),
+     wired on `change`. Audio on → soundtrack; **white-noise deferred** (removed from
+     the live control; `AUDIO_SOURCES={off,soundtrack}`; the pure pink-noise
+     machinery + tests stay for later).
+   - Video-off: `.black` gets `z-index:50` + `translateZ(0)` (own layer) **and** the
+     video layers are set `opacity:0` on video-off (belt-and-suspenders blanking).
+   - Safari audio: the tap-to-start gesture now primes both A/B `<audio>` elements
+     **synchronously in-gesture** (set src, vol 0, `play().then(pause)`), unlocking
+     the later async crossfades.
+   - Server: `player/audio.py` resolver + `controls.py`/`state.py` + `/api/alteration`
+     drop white-noise; `build_audio_media.py` stops emitting the noise bed.
+3. **Verify + ship.** Updated unit/contract/E2E tests; rewrote the 3 E2E for the new
+   toggles (click the visible `.dev-switch-track`; wait for the opacity transition).
+   **288 passed, 2 skipped.** Re-verified in **both Chromium and WebKit**: Audio toggle
+   plays `cosmos/pillars.loop.mp3`, video-off sets vid+paint opacity 0 with `#black`
+   shown, zero JS errors; screenshotted the new toggle UI. Merged `session-0021` →
+   `main` and pushed. (Also untracked a stray `docs/.threads/*.json` editor artifact
+   swept in by `git add -A`, and gitignored `.threads/`.)
+
+## Deferred decisions
+
+_No low-confidence calls. All three changes were explicit operator requests; the
+root-cause fixes (GPU z-index/layer-hide; Safari in-gesture unlock) are the standard
+remedies for these well-known browser behaviors._
+
+## Cut state
+
+- `main` @ `fddb6d6` (merge of session-0021), clean, pushed.
+- **288 tests + 3 Playwright E2E pass** (2 skipped: opt-in media integration).
+- White-noise is deferred, not deleted: `tools/pipeline/audio_ops.white_noise_args` +
+  `audio_run.generate_white_noise` + their tests remain; only the live control + the
+  build-script emission were removed.
+- **Unvalidated by this session:** real-device audio (Safari autoplay) and real-GPU
+  video-off — headless can't exercise either; needs the operator's by-ear/by-eye pass.
+
+## Operator plate
+
+- Video + Audio are simple on/off toggles (Dev-Mode style). Audio on = the current
+  altitude's soundtrack. The two real-browser bugs should now be fixed — but please
+  confirm on a real device (especially iPad/Safari).
+- Deferred: white-noise (easy to re-add as a 3rd Audio position), the per-altitude
+  music layer, the networked-control-surface build, Pi renderer.
+
+## Next /goal
+
+```
+/goal by-ear/by-eye review the audio + Video/Audio toggles on a REAL device (esp. iPad/Safari — headless can't validate Safari autoplay or GPU compositing), then source/compose the deferred per-altitude music layer per docs/audio-candidate-pool.md (or re-enable white-noise as a 3rd Audio position if wanted)
+```

sessions/0022/SESSION-0022.0-TRANSCRIPT-2026-06-26T08-40--2026-06-26T08-50.md

@@ -0,0 +1,79 @@
+# Session 0022.0 — Transcript
+
+> App: human-experience-filter-art
+> Start: 2026-06-26T08-40 (PST)
+> End: 2026-06-26T08-50 (PST)
+> Type: executing-plans (operator-driven follow-up to the audio feature)
+> Posture: yolo
+> Claude-Session: e0cc053a-41fa-416d-a4f5-493f14984e75
+> Status: FINALIZED
+
+## Launch prompt
+
+> (1) "It shouldn't say 'Tap to Start Sound'… it can start with both sound and video
+> off but immediately go to the app. We should have a 'Loading Universe…' loading
+> screen until all media has been downloaded and the experience is ready to run."
+> (2) "I still can't hear the sound, even in private mode."
+> (3) "The first time video is turned on, also turn on audio. If audio is turned on
+> before video after the app loads, just audio should turn on."
+
+## Pre-state
+
+- Sessions 0020/0021 had shipped the audio feature + a 0021 "Safari fix" (tap-to-start
+  overlay that primed A/B `<audio>` elements). The operator reported audio STILL
+  silent on their real browser (even in private mode), plus the UX requests above.
+
+## Session arc
+
+1. **Why the 0021 fix failed.** It primed *srcless* A/B elements in the tap gesture
+   and played the real audio in an *async continuation* (after `await fetch`). Safari
+   unlocks an element only when `play()` runs **synchronously inside** the gesture and
+   on an element **with a src** — so neither condition was met. Headless WebKit relaxes
+   autoplay, which is why automated tests never caught it.
+2. **Redesign (client-only, branch `session-0022`):**
+   - **Single `<audio id="aud">`** element (dropped A/B). It's played **synchronously
+     inside the toggle's own `change` handler** — the canonical Safari unlock. Altitude
+     changes reuse the now-unlocked element with a brief fade-swap.
+   - **"Loading Universe…" splash** (`#loading`, in the HTML so it shows pre-JS): `main()`
+     now `await`s `preloadAllMedia()` (driving a progress bar), then `hideLoading()`.
+     Replaces the tap-to-start wall.
+   - **Both toggles default OFF** (black + silent at start) — no autoplay needed until a
+     toggle is flipped.
+   - **First Video-on couples Audio:** the Video `change` handler, on the first on,
+     sets `#audio` checked and plays — in the same gesture (so it unlocks on Safari).
+     Audio toggled on first stays audio-only.
+   - Server contract unchanged (`{off,soundtrack}`); the client now drives playback
+     directly from the ring's `scale.audio`, ignoring `render.audio`.
+3. **Verify + ship.** Rewrote the 5 E2E for the new flow (single `#aud`, no gesture,
+   loading wait, the coupling, video-off blanking). Caught a test bug — `#black.hidden`
+   is `display:none`, so `wait_for_selector` default (visible) timed out; switched to
+   `state="attached"`. **290 passed, 2 skipped; 5 E2E pass.** Verified in headless
+   **Chromium AND WebKit**: first-Video-on couples audio, soundtrack plays, video shows,
+   zero JS errors; screenshotted the splash + running app. Merged to `main`.
+
+## Deferred decisions
+
+_No low-confidence calls — all three were explicit operator requests. The
+single-element synchronous-in-gesture play is the standard Safari remedy._
+
+## Cut state
+
+- `main` @ `4ac39c9`, clean, pushed. 290 tests + 5 Playwright E2E pass.
+- **Honest caveat — still unverifiable headlessly:** every engine Playwright ships
+  (Chromium, WebKit) relaxes autoplay, so I cannot *prove* real-Safari/iOS now plays.
+  The fix is the canonical pattern (sync `play()` in the gesture, real src) and is a
+  genuine change from 0021's broken approach — but it needs the operator's real-device ear.
+
+## Operator plate
+
+- No tap wall: "Loading Universe…" → app with both toggles off (black/silent). Flip
+  **Video** → video + audio together; flip **Audio** alone → audio only.
+- If sound is STILL silent on the real device, that points to something beyond autoplay
+  (codec/MIME, file, or element error) — next session should capture `aud.error` and the
+  exact browser.
+
+## Next /goal
+
+```
+/goal confirm on a REAL device (esp. iPad/Safari) that audio is now audible when Video/Audio is toggled on and the "Loading Universe…" → app flow feels right; if still silent, capture aud.error + the exact browser. Then the deferred per-altitude music layer per docs/audio-candidate-pool.md
+```

sessions/sessions.json

@@ -58,5 +58,11 @@
   },
   "0020": {
     "title": ""
+  },
+  "0021": {
+    "title": ""
+  },
+  "0022": {
+    "title": ""
   }
 }