toastsim/OPUS-BUILD-BRIEF-2.md

# TOASTSIM — Build Brief 2: The Prep Bench

**For: Claude Opus 4.8, executing in Claude Code on this Mac (M3 Ultra, cwd `/Users/m3ultra/Documents/toastsim`).**
**Approved by the owner. Asset generation via MODELBEAST is free and pre-authorized. Commit + push per milestone to `git@gitea.partly.party:monster/toastsim.git` (SSH remote already configured; HTTPS has no credentials).**

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## 0. Where you are standing

M0–M9 are shipped and verified: toasting (browning field), spreading (knife-angle rheology, butter/PB/MITEY/marmalade), the judged scorecard with a claymation judge, the tangled cutlery drawer, day loop with orders, oil-separation stirring, rind distribution scored by Clark–Evans, and a fresh-eyes pass (M9) that locked the cheat panel and added live readouts. **Read `README.md` and the git log first — the commit messages are design documents.**

**M10 (the bakery) is code-complete but NOT fully verified — that is your first job (§2).** It adds: bread brands with mechanical quality (`bread.ts` BRANDS), unsliced bakery loaves, a slicing minigame (`sim/slicing.ts` + `scenes/slicer.ts`), the bread knife and the legendary **The Best Thing** in the drawer, day 9, and cut quality feeding the toaster (wedge slices brown unevenly).

### How to run and verify (non-negotiable discipline)
- `npx vite --port 5173 --strictPort` in background; open via the Browser pane.
- **The embedded browser never fires rAF** (document.hidden is true) and can report `innerWidth 0`. The game survives both, and the dev harness exists because of them: `window.__t` (dev builds) drives the real input path deterministically — `t.run(frames)`, `t.tap('Space')`, `t.point(x,y,z,down)`, `t.toast(secs,power)`, `t.dip()`, `t.spread()`, `t.swirl()`, `t.stats()`, `t.look()`. Call `t.app.resize()` once after load. Extend the harness for every new minigame you build — if you can't drive it headless, you can't verify it.
- Verify by **playing and reading numbers the judge computes**, then screenshot. Never trust "it compiles". Every milestone: typecheck, build, played-through evidence, console clean, commit with a message that records what you *measured*, push.

### Known traps (all cost real debugging time once — don't pay twice)
- `THREE.Timer.connect(document)` freezes dt when hidden — don't reintroduce it.
- `camera.aspect = 0/0` poisons projection forever; `App.resize()` guards it — keep the guard.
- `mesh.rotation.x = -PI/2` on extrusions lays profiles out in opposite directions — use `extrudeFlat()` (geometry-level) in `cutlery.ts`.
- Rapier wants `{x,y,z,w}` quaternions, not arrays; array = NaN = wasm panic.
- Lathe profiles touching the axis = starburst normals. Build from primitives.
- Colours: palette is authored sRGB. `new THREE.Color(...floats)` reads as linear → pale. Use `.setRGB(..., THREE.SRGBColorSpace)`.
- ACES desaturates >1.0 — keep lighting products under 1.0 or yellow becomes cream.
- Shared materials can't do per-piece emissive — clone if you need highlights.

## 1. The design law (what made M0–M9 good — keep obeying it)

1. **Analog inputs, judged outputs.** Every mechanic is a continuous gesture the player can be *better at*, and every score is a statistic computed from the same state the gesture mutated. The scorecard always points at something real.
2. **Mistakes travel.** A bad cut toasts unevenly. Dawdling cools toast, which hardens butter. Never punish twice at the same station — punish downstream, where it's funny.
3. **Feedback before the verdict.** Live readouts use the judge's own functions (see kitchen's `amount` readout). The verdict may be brutal; it may never be a surprise.
4. **Statistics with names.** Clark–Evans for scatter, mass-weighted mean±stdev for consistency, CV for evenness. The judge quotes the number; the number is honest.
5. **Silhouettes are gameplay** → procedural geometry for anything the player must identify or that carries physics. Generated GLBs for hero props and vessels.
6. **The judge is the reward.** Every new criterion ships with ~5 bad lines + 3 good lines in his voice: dry, specific, never cruel except about MITEY.

## 2. M10 finish line — verify the bakery (do this first)

Everything compiles and day 9 reaches the drawer with the right ticket (verified: chips show `the bakery loaf / doorstop — slice it yourself`, timer reads "they are waiting", and the drawer contains `bread_knife` AND `the_best_thing`). Remaining:

1. Play the slicer end-to-end via harness: pick the bread knife from the drawer (drag it above the rim, hold 0.45s), aim ~0.31 world units (doorstop = 26–36mm at 110mm/unit), saw with vertical strokes (~0.05 units/frame stays under the squash threshold), confirm `onSliced` fires and the kitchen receives the cut.
2. Assert the couplings: a deliberate wobble cut (add dx while sawing) must show browning-evenness degradation after toasting (`stats().browning.stdev` visibly higher) and "a bit wedged" in The Cut row. A slam cut (fast dy) must arrive pre-damaged (Integrity).
3. Wrong-tool slicing: take the *soup spoon* to the loaf — confirm it's miserable but possible (saw eff 0.3) and the judge's Cut row + Utensil tell the story.
4. Tune feel: `STROKE_GAIN`, `WOBBLE_GAIN`, `SPEED_CAP` in `slicing.ts` are first guesses. A clean bread-knife cut should take ~4–6 deliberate strokes; The Best Thing ~3 and nearly wobble-proof. Cheap-brand WONDERSLICE toast (day 1) should visibly brown patchier than Crustworthy (day 8) — screenshot both.
5. The slicer scene has placeholder-quality visuals (flat crust box loaf, no cut seam). Minimum bar: a visible cut line that deepens with progress, the cut slice separating and falling flat at the end. Nice-to-have: crumb texture on the cut face (reuse `bread.crumb` colour).
6. `verify → commit → push` as **M10**.

## 3. M11 — The prep bench core (build once, everything else rides it)

A second bench (like the slicer scene) where ingredients get cut, and the machinery every later milestone uses.

### 3.1 Ingredients
`src/sim/ingredients.ts`:
```ts
interface Ingredient {
  id: string; name: string;
  shape: 'sphere' | 'ovoid' | 'block' | 'wedge' | 'bulb';
  size: number;                    // world units, 1 ≈ 11cm
  skin:  { resistance: number; slippery: number };  // tomato: low res, HIGH slip
  flesh: { resistance: number; moisture: number; layered?: boolean }; // onion: layered
  seeds?: { count: number; pocket: 'core' | 'distributed' };
  sting?: number;                  // onions
  temp?:  { state: 'fridge' | 'bench'; softensInSec?: number; needsSoft?: boolean; needsCold?: boolean };
  gratable?: { yield: number; pithDepth?: number };  // citrus zest / hard cheese
  roastable?: boolean;
}
```
Starting cast: `tomato` (slippery, wet), `roast_tomato` (wetter, softer), `orange` (ovoid, seeds, zestable), `onion` (layered, sting 1.0), `garlic` (bulb, small), `parmesan` (block, needsCold, gratable), `brie` (wedge, needsSoft), `cucumber`, `avocado` (seed = one giant pit, flesh softness varies by *ripeness* roll — a free lottery joke).

### 3.2 Generalized cutting (`src/sim/cutting.ts`)
Extract and extend the M10 slicing sim. A `CutSession` = ingredient + knife + a **pattern**:
- `halve` — one cut; scored on evenness of the two halves (offset from centre + wedge).
- `slices(n)` — repeated cuts; pieces recorded as widths → **evenness = coefficient of variation** of piece volumes. CV < 0.08 "even", > 0.25 "a lottery".
- `dice` — two-phase (see onions, §6).
- `wedges(n)` — radial; for oranges/tomato wedges.

New physics on top of M10's progress/wobble/squash:
- **Slip**: on the first bite, if `skin.slippery * downforce > grip`, the ingredient *skates* — the cut position jumps, juice sprays (→ mess field), and you re-aim. Grip comes from saw motion (a moving serrated blade bites; pressing a chef's knife straight down on a tomato is the canonical failure). The Best Thing and sharp knives bite at low downforce.
- **Juice**: every cut through `flesh.moisture > 0.4` ejects juice proportional to moisture × speed, sprayed along the stroke direction (→ mess field §3.3). Slow deliberate cuts leak less. Roasted tomatoes are basically water balloons — the joke is intended.
- Pieces are physics bodies on the board when it matters (dice results tumble; reuse drawer's compound-collider discipline — primitives, never trimesh).

### 3.3 The mess field (`src/sim/mess.ts`) — the bench is judged now
A `Field` over the cutting-board UV (reuse `core/field.ts` wholesale) + a particle list for solids (seeds, skins, zest, crumbs — reuse the rind instancing pattern from `slice.ts`).
- Writers: juice spray, seed ejections, onion skins, grated overflow, squashed pulp.
- Wipe tool: hold-and-drag a cloth (same brush machinery as spreading, in reverse). Wiping costs service time. Wiping juice *spreads it thinner first* (mass-conserving brush: same trick as butter) before absorbing — one pass smears, two passes clean. That's the feel.
- Judge criterion **The Bench** (weight ~0.9) on any prep order: mess mass + spread fraction, worded by the worst contributor: "There is juice on everything. Everything." / "Somebody's seeds are on my floor." Good: "A clean board. You'd be surprised how rare."
- Live readout in the prep HUD: `bench: clean / smeared / a crime scene` — judge's own thresholds.

### 3.4 Scoring plumbing
Orders grow a `prep?: PrepStep[]` list; the judge gains a per-step criterion builder (cut evenness, yield, pith, sting-time, bench). Group the scorecard visually by station (Prep / Toast / Spread) — the card is getting long, and grouping keeps it legible.

## 4. M12 — Oranges and the ribbed pyramid

**Flow: (zest first, if ordered §5) → halve → juice → serve the glass.**

- **Halving** uses `halve` pattern. Cut-quality → **theoretical yield**: `yield = base × (1 − 2|offset|) × (1 − 0.5·wedge)`. A perfect halve leaves 100% reachable; a 60/40 butchering caps you at ~70% and the judge will say why: "You have cut a lid and a bucket."
- **The juicer** (hero prop: old-school ribbed glass pyramid — generate it). Minigame reuses the *jar-stir swirl detection* (kitchen.ts) verbatim: place the half (drag onto cone), then **press + twist**. Twist sweep extracts (`extracted += sweep × pressGrip`); pressing hard *without* twisting tears pulp (mess + pulp-in-juice) and sprays. Yield bar fills toward the theoretical max — the live readout says `62% of what this orange had`. Rotate rhythm matters: reversals of twist direction give a small bonus bite (real reamers work this way; it also just feels right).
- **Seeds.** Each orange carries `seeds.count` (3–7). The Pyramid Classic (starter) lets seeds through into the glass: visible, clickable — fish each out at a time cost, or serve pips and eat the criterion: "There are three pips in this. I counted. I shouldn't have been able to."
- **Juicer tiers** (progression, introduced by day like brands): `Pyramid Classic` (day 12) → `Ribbed Deluxe` (seed moat catches ~80%) → **`The Juicernaut`** (legendary, day ~20 procedural rare: catches everything, +10% yield, and the judge notices: "Is that a Juicernaut. Sit down.").
- Judge criteria: **Yield** (vs theoretical, weight 1.3), **Pips** (1.1), **The Bench**, plus the halve's Cut row. Serve = the glass on the pedestal instead of toast — `JudgeView.show` needs a `subject` abstraction (toast mesh | glass mesh). Keep it small: a presented `Object3D` + criteria list.

## 5. M13 — The grater

One prop (box grater generated; microplane optional later), two customers:

- **Zest**: before juicing, some orders want `zest of one orange`. Hold the orange against the grater, rhythmic vertical drags = zest particles (distance-based shedding — the marmalade-rind pattern, reused exactly). **The pith line**: each surface region has `zestDepth`; over-grating a region past `gratable.pithDepth` sheds white pith particles into the pile — visible (white among orange), and the judge's **Pith** criterion counts the ratio: "This zest is half pith. It will taste like a headache." Scroll wheel rotates the orange to expose fresh skin — the skill is *rotation discipline*, same muscle as rind-scatter.
- **Cheese**: parmesan (needsCold) grates clean IF cold — it softens on the bench in real time, and soft parmesan (or brie, ever) **smears**: output drops, the grater clogs (a clog meter; clearing it costs time), mess accrues. The inversion of butter: butter wants warm, cheese wants cold, and both run on the same temperature clock (§7). 
- **Knuckles**: grating speed over a threshold rolls a knuckle graze — small Integrity-style penalty on the *player* (brief red flash, mess spot, and a line: "That's your knuckle in there. I'm not scoring the protein.").
- Judge criteria: **Zest/Gratings amount** (band, like spread amount), **Pith**, **Clog/mess**.

## 6. M14 — Onions (the technique test)

- **The sting.** While an onion is cut open, sting pressure rises (rate × `sting` × cut aggression — crushing cuts sting more, so blunt knives and squash-heavy strokes are literally tear gas). Rendered as a growing edge-blur + welling vignette (CSS overlay, cheap). Vision cost is REAL: it blurs the cut line and the stop-line marker. Options with costs: wipe eyes (button: clears it, 4s, and if you've been handling onion it *doubles* it first — once, for the joke and the lesson), push through, or work fast and clean. Sharp knife + low squash = slow sting. The Best Thing is, again, the best thing.
- **The proper dice** — exactly the technique the owner described: 
  1. Halve stem-to-root. 
  2. Lay flat. Radial/parallel cuts toward the stem **that must STOP short of it** — a visible stop-line at ~85%; a cut that goes through the stem releases the layers early (pieces fall apart into slivers — layered flesh means the CV of your final dice explodes). Undercutting leaves connected chunks (also CV chaos, other direction).
  3. Rotate 90° (scroll wheel), **criss-cross** cuts → dice falls in cubes.
- Scored on **Dice CV** (the piece-evenness statistic from §3.2 — this is where it shines), stem discipline (through-cuts counted), sting time endured, bench state (onion skins are mess solids).
- Judge lines: "You went through the stem. The onion became confetti. You served confetti." / good: "Square. Actually square. I'm keeping one."

## 7. M15 — Bruschetta (the capstone that uses everything)

The multi-component order. The ticket becomes a small recipe card; service time weight rises; **planning is the mechanic**:

- **Temperature clock** (generalizes butter softness): ingredients have bench-vs-fridge states drifting on real time. Brie must come out EARLY (soft enough to spread by assembly time); parmesan must stay in UNTIL needed. The ticket hints ("get the brie out now, love") and a small fridge/bench toggle UI per perishable — decided at order start and revisitable at a time cost.
- **Roast tomatoes**: the oven is the toaster generalized — reuse the browning Field on tomato halves (they blister rather than brown: same field, different colour ramp + a `blister` speckle past 0.6). Overdone = collapse into sauce (moisture → mess when handled).
- **Assemble**: your OWN sliced sourdough (M10), toasted (M1), rubbed with garlic (one swipe mechanic — a light 'spread' with a garlic clove, coverage judged lightly), topped: tomato pieces + cheese + basil. **Topping distribution = Clark–Evans again** (the rind code takes a point list — feed it topping placements). **Balance**: total topping mass per slice area band, "thicker but even and balanced = more score" — mass band × distribution, the user's exact ask.
- **The sog clock**: wet toppings on toast start `sog` rising (rate × topping moisture ÷ slice thickness — thick doorstop slices resist sog: ANOTHER reason the bakery loaf matters). Serve before soggy; the judge presses a finger on it, on camera: "It bends. Toast should not bend."
- Judge screen groups: The Bread (cut+toast) / The Topping (distribution, balance, sog) / The Bench. This is the order type where an S feels like a diploma.

## 8. Assets — MODELBEAST (all free, all local; fire jobs FIRST, code while they run)

`scripts/gen-assets.sh` has the pipeline (`gen_3d name seed "prompt"`; flux → bg_remove → hunyuan3d, ~6 min each, GPU lane serial). **The M10 bakery batch partially failed** — `sourdough_loaf` meshed but produced no GLB, and `batard_loaf`, `cutting_board`, `tomato_vine`, `roast_tomatoes` failed at flux. First: check `./mb jobs` (source `~/Documents/MODELBEAST/data/agent.env`) for the error text, re-run with bumped seeds (+1) and slightly reworded prompts; add a retry-once into `gen_3d`. Never spam retries on `queued` — the lane is serial and shared.

Then queue the prep-bench cast (fixed seeds, style token as in the script): oranges ×2 (whole / halved showing segments), ribbed pyramid juicer (hero — prompt the ribs explicitly), juice glass, box grater, brown onion, garlic bulb, basil sprig, olive-oil bottle, oven tray, Ribbed Deluxe + Juicernaut juicer variants, plus 2D: bruschetta title-hero, "WONDERSLICE" bag art for the ticket. Anything the player must *identify by shape* or that carries physics (onion halves, dice pieces, orange halves on the reamer) stays **procedural** — silhouettes are gameplay, and meshers hate thin/segmented geometry.

## 9. Milestone order, and the bar for each

M10-verify → M11 → M12 → M13 → M14 → M15, one commit+push each, message = what you measured. For each: harness helpers first, then the sim (pure, in `src/sim/`), then the scene, then judge criteria + 8 lines, then live readouts, then played-through verification with numbers in the commit message, then screenshots. If a milestone's *feel* is wrong, fixing feel beats advancing — the loaf, the reamer twist and the onion stop-line are the three feels that must be RIGHT.

Pre-authorized judgment calls: all tuning constants; cutting scope inside a milestone to protect feel; procedural-vs-generated per asset; deferring the microplane, avocado, cucumber if the core five (orange, onion, tomato, parmesan, brie) land better without them. Do NOT add paid/cloud dependencies, accounts, or telemetry. Do not touch `~/Documents/MODELBEAST` except through `mb`.

The bet is the same as last time: the bones are good, so build each new station on the bones — Fields, point-statistics, distance-shedding, swirl detection, dwell commits, the harness — and the game stays one game instead of six minigames in a trench coat.