LANE-JUICE2: session block — ear pass is rigged and waiting on ears

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

LANEHANDOVER.md

@@ -597,3 +597,70 @@ heat).
 (files in lanes/). All three parallel, worktrees, own branches, usual protocol.
 If only one session: CONTENT first (it's the game's heart), FLOOR2, then JUICE2
 — except run JUICE2 first if John is available for the ear pass.
+
+---
+### SESSION — LANE-JUICE2 — 2026-07-19 21:50
+**Branch/commits:** lane/juice2 @ d112bda..1a66c60 (worktree `../not-tonight-juice2`)
+**Done:**
+- **`audio/mix.ts` + `audio/arc.ts`** (new, pure, tested). The track's constants
+  are now a live `TrackMix`, and the night has a shape. Same surface serves the
+  ear pass, the arc, and the Phase-4 DJ control panel (BUILD_PLAN §4 rule).
+- **`TechnoEngine`** drives every voice from the mix × arc scalars. Verified
+  behaviour-identical at `DEFAULT_MIX`, constant by constant. Silent voices are
+  skipped rather than clamped (9 PM bass builds zero nodes). `setMixValue`
+  quantises integer paths so the dump can't export a value nobody heard.
+- **`ui/MixDeskScene`** — the ear-pass rig. Solo/mute per voice with a
+  per-voice listening prompt, every param on log-mapped sliders (5 pages), an
+  arc scrubber, and DUMP MIX → pasteable `TrackMix` literal + clipboard.
+  Restores the arc pin and solo state it found, so it can't un-tune its host.
+- **`audio/Ambience`** — rain (outside), crowd murmur (inside, level follows the
+  room), kebab-shop fluoro hum. See routing + headcount notes below.
+- **`Phone`** thread scrolls: visible-window culling, binary-searched range,
+  history cap, sticky-bottom, and a "NEW BELOW" cue when a text lands off-screen.
+- **`JuiceDemoScene`** hosts all of it; arc pinned at PEAK on entry.
+**How to see it:** the demo lives in this worktree, so
+`cd ../not-tonight-juice2 && npx vite --port 5311` → http://localhost:5311/#juice
+(or J). Click once to unlock audio, then **M** for the mix desk.
+**Tests:** 460 passing / 0 failing (was 413; +45 across mix/arc, +2 from fixes).
+**Verified by ear:** STILL NOTHING — no audio output in this environment. Logic
+verified in a real browser: arc pins/restores across desk open+close, integer
+quantisation, crowd headcount arithmetic (120 + 2 admits − 1 ejection = 121 with
+the clicker event correctly ignored), zero console errors.
+**THE ASK — the ear pass is now a ~10 minute job and I can't do it:**
+Open the desk, SOLO each voice in turn, fix what's wrong, hit DUMP MIX, paste me
+the literal. It goes straight over `DEFAULT_MIX` in `src/audio/mix.ts`.
+`tests/mix.test.ts` pins the current values deliberately, so a retune will fail
+that test — that's the tripwire working; update it in the same diff. Specifically
+unjudged: does the kick read as a kick through the door filter, is the bassline
+musical or just busy, is `typeTick` (fires per character) tolerable, does the
+stamp sit right against the music, and does the door→floor sweep feel like a door.
+**Broke / known-wonky:**
+- `Ambience` rain uses `Sfx`'s own 1.2s/0.9s envelope, so it trails the 600/900ms
+  filter sweep by ~300ms. Fixing it properly means a `fadeS` param on
+  `Sfx.startRain/stopRain`. Reads fine; noting it rather than hiding it.
+- `Ambience` assumes it is the sole owner of rain policy. If a door scene also
+  drives `sfx.startRain()` they will fight.
+- `MixDesk` is reachable only from JuiceDemo (key M) — see request 1.
+- No `TechnoEngine`/`Ambience` test files; both need a real `AudioContext` and
+  the suite is node. Their pure math is tested via mix/arc/scheduling/filterCurve.
+**Contract change requests:** none. `door:phoneTheatre` was folded in at the
+Phase-1 review; the crowd bed derives its headcount from existing events rather
+than requesting `capacity.inside` in a payload (reasoning above).
+**Requests for integration (main.ts is yours now, per the Phase-1 ruling):**
+1. **A global route to the mix desk**, so the ear pass can also happen during a
+   REAL night rather than only in the demo. `MixDeskScene` already falls back to
+   `getActiveEngine()` when launched without data, so it attaches to whatever
+   engine is running — it just needs a key. Suggest **M**, alongside N/P/F/J.
+2. Optional: `MeterHud` door-bar variant is still not done (LANE_JUICE2 §4.3,
+   explicitly "only if clean"). DoorScene's bespoke meters work; I left them.
+**Questions for reviewer:**
+1. The arc means the night no longer sounds the same at 9 PM and 1 AM — bass is
+   fully out at 9 PM by design. Worth confirming that's wanted before John tunes
+   against it, since it changes what "the mix" even means at a given hour.
+2. `Ambience` currently has no owner in `NightScene` — I can't wire it there
+   (scenes aren't mine). Want it created alongside TechnoEngine at integration?
+**Next session should:**
+- Run the ear pass with John and land the retuned `DEFAULT_MIX`.
+- Wire `Ambience` into `NightScene` (integration-owned).
+- LANE-FLOOR2 owns the cut-off overlay call site; `DialogueBox` drunk-typo mode
+  is ready for it and needs no widget change — just pass `drunkenness` + `rng`.