HardYards/web/world/js/weather.js

'use strict';
// SHADES — Lane C — weather: the wind field everyone samples.
//
// Implements the contracts.js wind surface (PLAN3D §4):
//   wind.sample(pos, t) -> Vector3        m/s, includes gusts & local effects
//   wind.gustTelegraph(t) -> {eta, dir, power} | null
//
// All the maths lives in weather.core.js (pure, no imports). This file is just
// the THREE adapter + storm loading, so the sim stays node-testable and the
// determinism rule can't be broken by accident.

import * as THREE from '../vendor/three.module.js';
import {
  createWindField, validateStorm, validateSiteWind, GUST, RAIN_TIME_COMPRESSION,
  hailBlockFor, stormStats, forecastFor,
} from './weather.core.js';

export {
  GUST, validateStorm, validateSiteWind, RAIN_TIME_COMPRESSION,
  hailBlockFor, stormStats, forecastFor,
};

const kmh = (ms) => ms * 3.6;
const band = (b, fmt) => (b.hi - b.lo < 0.05 ? fmt(b.lo) : `${fmt(b.lo)}–${fmt(b.hi)}`);

// SPRINT16 gate 3.3's word map, lifted to module scope in S17 so the honesty
// gate below audits THE map the card prints from — a predicate checking a copy
// of the vocabulary would agree with the copy forever, which is the exact drift
// this repo keeps getting bitten by. Words map hail.size units (1.0 ≈ a 1.5 cm
// stone): storm_03's 0.7 reads "pea" (its own comment's word), the soaker's
// 0.45 "fine pea", the wild night's 1.3 and the ice night's 1.4 read "golf
// balls" — the sizes cloth stops dead.
const stoneWord = (v) => (v < 0.6 ? 'fine pea' : v <= 0.9 ? 'pea' : v <= 1.2 ? 'marble' : 'golf ball');

/**
 * Where the stone vocabulary stops being honest. "golf ball" is the map's
 * biggest word and it is open-ended upward — a storm whose stones measure 2.6
 * would still print "golf ball stones", underselling ice the way the numbers
 * are forbidden to. The numeric bands stay truthful at any size (band() can't
 * lie), but the card leads with the WORD, and a word that rules out what
 * actually falls is the same ambush as a band that does. 2.0 is where the line
 * sits: at 1.0 ≈ 1.5 cm, 2.0 ≈ 3 cm is real golf-ball territory, so the word
 * holds all the way up to it; past it we are in cricket-ball country the map
 * has no word for. Shipped max is the ice night's 1.4 — real headroom, hard
 * ceiling. A storm above this is unofferable until the vocabulary grows a word
 * for it, and that is a wording sprint, not a data tweak.
 */
export const STONE_WORD_CEILING = 2.0;

/**
 * How vague a night reads when it is `nightsOut` nights away — the week IS the
 * forecast horizon, so tonight is exact (0) and the far end of the week is as
 * vague as this game forecasts (1). Linear, because that maps the week onto
 * forecastFor's documented 0..1 domain with nothing invented in between.
 *
 * For a five-night week: tomorrow reads at lead 0.25 — 75% confidence, a
 * sustained band about ±8% wide. Visibly hedged, still worth rigging to.
 *
 * Lane A: this is the job sheet's missing argument. `forecastLines(def, 0)` is
 * tonight; `forecastLines(tomorrowDef, leadFor(1, wk.nights))` is tomorrow's
 * band. Nights beyond the week (or a one-night week) clamp to 1 and 0.
 *
 * @param {number} nightsOut  0 = tonight, 1 = tomorrow
 * @param {number} [weekNights] nights in the week (5)
 * @returns {number} lead, 0..1
 */
export function leadFor(nightsOut, weekNights = 5) {
  if (!(nightsOut > 0)) return 0;
  const horizon = weekNights - 1;
  if (!(horizon > 0)) return 1;      // a one-night week: anything but tonight is a guess
  return Math.min(1, nightsOut / horizon);
}

/**
 * The forecast card's two stat lines, already worded — DESIGN.md's partial
 * information made visible. Lane A owns the card; this owns the numbers, so the
 * card stays one call instead of re-deriving the storm inline.
 *
 * `lead` is how far out the night is: 0 = tonight (exact numbers, reads exactly
 * as the card always has), 1 = the far end of the week (wide bands, low
 * confidence). The bands ALWAYS contain the truth — a forecast may be vague but
 * it must never rule out what actually happens, or a player who rigs for the top
 * of the stated range gets ambushed.
 *
 * Numbers are MEASURED (stormStats), not estimated: the card's old inline
 * `baseCurve peak + powBase + powRamp` read 30 m/s for storm_02, which really
 * gusts to 32.3, because gust power is drawn per gust and rides a ramp.
 *
 * @param {object} def   parsed storm JSON
 * @param {number} [lead] 0..1
 * @returns {{name, night, wind, rain, confidence, hail, truth}}
 */
export function forecastLines(def, lead = 0) {
  const f = forecastFor(def, lead);
  const i = (v) => v.toFixed(0);

  const sustained = band(f.sustained, i);
  const gusts = band({ lo: kmh(f.gustPeak.lo), hi: kmh(f.gustPeak.hi) }, i);
  const sustainedKmh = band({ lo: kmh(f.sustained.lo), hi: kmh(f.sustained.hi) }, i);

  // rain reads as a word, and a vague forecast hedges across two
  const word = (v) => (v >= 0.8 ? 'heavy' : v >= 0.4 ? 'steady' : 'light');
  const rainWord = word(f.rain.lo) === word(f.rain.hi)
    ? word(f.rain.hi) : `${word(f.rain.lo)}–${word(f.rain.hi)}`;

  const change = f.changeAt
    ? `· southerly change ${lead > 0 ? band(f.changeAt, i) + 's' : `at ${i(f.changeAt.lo)}s`}`
    : '· no change forecast';
  const hail = f.hail.chance === 'none' ? '' : `· hail ${f.hail.chance}`;

  // SPRINT16 gate 3.3 — the stone and the rain RATE join the card (A prints
  // them; this owns the wording, same split as every other line here). The
  // stone is the fabric bet's whole argument: pea hail rattles through a
  // 2 mm weave, anything bigger cannot — so the size word is what tells a
  // player which fabric tonight wants, before a dollar is spent. The word map
  // itself is module-scope now (S17) — the offer-honesty gate audits it.
  const sz = f.hail.size;
  const stones = f.hail.chance === 'none' ? '' : (
    stoneWord(sz.lo) === stoneWord(sz.hi)
      ? `${stoneWord(sz.hi)} stones`
      : `${stoneWord(sz.lo)}–${stoneWord(sz.hi)} stones`
  );

  return {
    name: (def.name ?? '').replace(/_/g, ' ').toUpperCase(),
    night: (def.sky?.night ?? (def.sky?.darkness ?? 0) > 0.6),
    wind: `sustained to ${sustained} m/s (${sustainedKmh} km/h) · gusts to ~${gusts} km/h`,
    rain: `rain ${rainWord} ${change} ${hail}`.trim(),
    // The gate-3.3 lines, separate fields so A's card can place them without
    // re-deriving anything. Empty string = nothing to print, same rule as
    // `confidence` below; both bands contain the truth at every lead.
    rainRate: `rain to ${band(f.rainMmPerHour, i)} mm/hr`,
    stones,
    // Only worth showing when it isn't tonight — "CONFIDENCE 100%" is noise.
    confidence: lead > 0 ? `forecast confidence ${Math.round(f.confidence * 100)}%` : '',
    hail: f.hail,
    truth: f.truth,
  };
}

/**
 * SPRINT17 gate 1 — CAN THE FORECAST DESCRIBE THIS STORM HONESTLY?
 *
 * The board's rule, stated in A's seam contract and enforced here: *a storm the
 * forecast can't describe honestly doesn't get offered.* An offer card leads
 * with my lines — if those lines can't tell the truth about a def, the def has
 * no business on the board, however winnable the pairing is. c.test walks
 * NIGHTS ∪ POOL through this, so a new pool entry (D's yard, arc-4 seeds)
 * meets the gate at integration without anyone remembering to ask.
 *
 * Same contract shape as validateStorm: {ok, errors}, errors in English,
 * recomputed FROM THE DEF — nothing here trusts the caller's provenance, so a
 * hand-edited def fails on its own merits (the checkEnvelope rule).
 *
 * What has TEETH here, disclosed plainly (README: an assert that cannot fail
 * is decoration):
 *   · validateStorm — structural lies (a windchange the dirCurve never
 *     delivers, overlapping gusts, a flatlining tail) really do fail.
 *   · the stone vocabulary ceiling — a def with stones past STONE_WORD_CEILING
 *     really does fail (the icenight at hail.size 2.6 is the negative control).
 *   · finiteness of the measured stats — a curve that produces NaN fails.
 * What is STRUCTURAL and rides along as regression armour, not as a live gate:
 * band-contains-truth and lead-0 exactness are guaranteed by forecastFor's
 * band() today (lo=min(v,·), hi=max(v,·), width→0 at lead 0) — those loops can
 * only fail on the day someone re-plumbs band(), which is precisely the day
 * they should. Disclosed here and in THREADS rather than dressed up as
 * coverage.
 *
 * @param {object} def  parsed storm JSON
 * @param {string} [name]
 * @returns {{ok: boolean, errors: string[]}}
 */
export function forecastHonest(def, name = def?.name ?? 'storm') {
  const errors = [];
  const v = validateStorm(def, name);
  if (!v.ok) errors.push(...v.errors);
  if (!def || typeof def !== 'object' || !v.ok) return { ok: false, errors };

  // The truth must be measurable before it can be told.
  const s = stormStats(def);
  for (const k of ['sustained', 'gustPeak', 'rainPeak', 'rainPeakMmPerHour',
                   'hailPeak', 'hailSeconds', 'hailSize']) {
    if (!Number.isFinite(s[k])) {
      errors.push(`${name}: stormStats.${k} is not finite — no honest line can be printed from it`);
    }
  }

  // The vocabulary must reach the stone. Numbers band honestly at any size;
  // the WORD is the card's opening argument and it must not undersell ice.
  if (s.hailSeconds > 0 && s.hailSize > STONE_WORD_CEILING) {
    errors.push(`${name}: hail.size ${s.hailSize} is past the stone vocabulary's ceiling `
      + `(${STONE_WORD_CEILING}) — "${stoneWord(s.hailSize)}" would undersell what falls; `
      + 'grow the word map before offering this storm');
  }

  // Recompute the band promises from the def (structural today — see header).
  const contains = (b, val, what, lead) => {
    if (val == null || b == null) return;
    if (!(Number.isFinite(b.lo) && Number.isFinite(b.hi))) {
      errors.push(`${name}: ${what} band at lead ${lead} is not finite`);
    } else if (val < b.lo - 1e-9 || val > b.hi + 1e-9) {
      errors.push(`${name}: ${what} band [${b.lo}, ${b.hi}] at lead ${lead} rules out the truth ${val}`);
    }
  };
  for (const lead of [0, 0.5, 1]) {
    const f = forecastFor(def, lead);
    contains(f.sustained, s.sustained, 'sustained', lead);
    contains(f.gustPeak, s.gustPeak, 'gustPeak', lead);
    contains(f.rain, s.rainPeak, 'rain', lead);
    contains(f.rainMmPerHour, s.rainPeakMmPerHour, 'rainMmPerHour', lead);
    contains(f.hail.seconds, s.hailSeconds, 'hail.seconds', lead);
    contains(f.hail.size, s.hailSize, 'hail.size', lead);
    contains(f.changeAt, s.changeAt, 'changeAt', lead);
    if (lead === 0) {
      for (const [what, b] of [['sustained', f.sustained], ['gustPeak', f.gustPeak], ['rain', f.rain]]) {
        if (b.lo !== b.hi) errors.push(`${name}: lead-0 ${what} band [${b.lo}, ${b.hi}] hedges — tonight is exact`);
      }
      if (s.hailSeconds > 0 && f.hail.chance === 'none') {
        errors.push(`${name}: hails for ${s.hailSeconds.toFixed(1)}s but tonight's card says "none"`);
      }
    }
  }

  return { ok: errors.length === 0, errors };
}

// ─────────────────────────────────────────────────────────────────────────────
//  THE OFFER BAND, and THE PAIRING HALF OF THE GATE (SPRINT17 gate 1)
//
//  Landed ON TOP of forecastHonest above, by the other half of Lane C this
//  sprint — two sessions converged on gate 1 and split it cleanly without
//  meaning to. `forecastHonest` answers "can the forecast describe this STORM",
//  which is the storm-side gate and stays exactly as it landed. These two add
//  the parts it does not reach: WHAT THE CARD ACTUALLY PRINTS, and WHICH YARD
//  the storm may be printed over. Nothing above this line was changed.
// ─────────────────────────────────────────────────────────────────────────────

/**
 * THE HONEST BAND FOR AN OFFER CARD — an ORDERED LIST of lines, not a bag of
 * named fields, and the shape is the whole point.
 *
 * ⚠️ **WHY A LIST, when `forecastLines` already returns every string a card
 * could want.** A card that reads named fields prints the fields its author
 * remembered. A's board shipped `f.wind` and `f.stones` — a reasonable pair —
 * and that pair MEASURABLY LIES ABOUT NIGHT 7:
 *
 *   | night 7's two offers | wind line | stones line |
 *   |---|---|---|
 *   | the soaker (scripted) | gusts to ~55 km/h | fine pea stones |
 *   | the early buster (alt) | gusts to ~76 km/h | pea stones |
 *
 * On both printed lines the soaker is the SOFTER job. It is not: it delivers
 * **14.9 s of hail against 2.4 s, and 44 mm/hr of rain against 16.5**. The
 * soaker's whole design is that its wind reads gentle while its hail is the
 * trap (C, S16 gate 3.1) — so a board printing only wind and stone size
 * recommends the trap, in the storm's own voice, before a dollar is spent.
 *
 * The fix is not "also print rainRate". The fix is that the FORECAST decides
 * which facts a night carries and hands over all of them, so the next fact
 * added to a storm cannot be silently dropped by a card that predates it. Same
 * construction, and the same reasoning, as A's `stormsToPreload(nights, pool)`
 * split: an omission that is possible will eventually happen.
 *
 * ⚠️ **It never renders MORE than the truth either.** A hail line appears if and
 * only if the storm hails — "hail: none" on a hail-free night teaches that the
 * absence of a hail line means nobody checked.
 *
 * @param {object} def   parsed storm JSON
 * @param {number} [lead] 0..1 — the BOARD passes 0, and only 0: both offers are
 *   for TONIGHT. You are choosing which yard to stand in, not which night to
 *   work, and a hedged board would invent uncertainty the job sheet contradicts
 *   one card later.
 * @returns {{key:string, text:string}[]} reading order: wind, hail, rain,
 *   change, confidence. `key` is for styling; `text` is the whole printed line.
 */
export function offerBand(def, lead = 0) {
  const f = forecastLines(def, lead);
  const ff = forecastFor(def, lead);
  const t = f.truth;
  const i = (v) => v.toFixed(0);
  const lines = [{ key: 'wind', text: f.wind }];

  // Hail, with its DURATION. `chance` at lead 0 is a duration threshold wearing
  // a probability word (hailSeconds > 6 ⇒ 'likely'), which is honest enough on
  // a job sheet and far too coarse on a board where two hail nights sit side by
  // side: 'likely' covers both the soaker's 15 s and the ice night's 21 s, and
  // 'possible' covers the buster's 2.4 s. The seconds are what a tradie buys
  // steel against, so the seconds print.
  if (f.stones) {
    lines.push({
      key: 'hail',
      text: `hail ${f.hail.chance} · ${f.stones} · ${bandStr(ff.hail.seconds, i)}s of it`,
    });
  }

  // The rain RATE, always — the line A's card had no field for, and half of the
  // soaker's trap. mm/hr is the unit the ponding model reads, so the card and
  // the sim agree on what "heavy" means instead of each having an opinion.
  lines.push({ key: 'rain', text: f.rainRate });

  // The change, always — including "no change forecast", which is information,
  // not filler. storm_03_southerly and storm_03b_earlybuster are IDENTICAL in
  // every other number this band prints (sustained 13.0, gustPeak 21.4/21.2,
  // rain 16.5 mm/hr, hail 2.4 s at size 0.70) and differ ONLY in when the change
  // lands, 30 s against 18 s. The board offers exactly that pair — the buster is
  // the drawn alternative on nights 5 and 7. Drop this line and the board offers
  // two jobs whose weather it has just claimed to describe, described
  // identically, and calls it a choice.
  lines.push({
    key: 'change',
    text: t.changeAt == null ? 'no change forecast'
      : (lead > 0 ? `southerly change ${bandStr(ff.changeAt, i)}s`
                  : `southerly change at ${i(t.changeAt)}s`),
  });

  if (f.confidence) lines.push({ key: 'confidence', text: f.confidence });
  return lines;
}

/** `band` under its own name — the module-scope helper, reused rather than retyped. */
function bandStr(b, fmt) { return band(b, fmt); }

/**
 * ⚖️ **THE PAIRING LAW — which yards a storm may be OFFERED over.**
 *
 * `forecastHonest` above asks whether the forecast can describe a STORM. This
 * asks the other half of SPRINT17 gate 1's rule, the half that is a fact about
 * GEOMETRY × STORM rather than about wording: a band can be perfectly honest
 * about a storm and still be an invitation to a night nobody can work.
 *
 * ⚠️ **These three were three prose comments before they were a rule.** A's POOL
 * carries them as a comment listing what is "deliberately NOT here" — and this
 * repo's standing verdict on that arrangement is A's own, on CONSTRAINT_KIND:
 * an unenforced enum is decoration, and the carport shipped typed as a post for
 * a sprint behind a JSDoc comment saying it couldn't. A comment cannot fail when
 * somebody adds the sixth pool entry. Promoted to data, checked, red in the suite.
 *
 * **A — two of these three are YOUR reasons and are recorded as yours.** I have
 * not re-measured a separation pin or a beyond-saving flag; I have moved your
 * stated grounds into a structure that goes red. Reword freely — the mechanism
 * is what I am defending, not the prose.
 *
 * An absent key means UNRESTRICTED, deliberately: this table records refusals
 * somebody PAID FOR, and inventing one for a pairing nobody flew is the same
 * offence in the other direction.
 */
export const PAIRING_LAW = Object.freeze({
  storm_06_soaker: {
    sites: ['site_02_corner_block'],
    owner: 'C',
    why: 'MEASURED (C, S16 gate 3.1, both shipped yards flown through gardenfly before the '
       + 'storm shipped): backyard_01\'s buyable geometry caps hail cover over the bed at '
       + '~31%, and its full-cover quads pond-tear at 3.3–3.7 kN in this mild wind on BOTH '
       + 'fabrics — best membrane line 37.5 against cloth 17.3, a fabric bet with no win in '
       + 'it. The soaker\'s forecast reads "fine pea stones · rain to 44 mm/hr" over there '
       + 'exactly as it does over site_02, and over there that band is an invitation to a '
       + 'night nobody can work. The swing lawn is not measured under it at all, which is '
       + 'the same refusal for a cheaper reason.',
  },
  storm_02_wildnight: {
    sites: ['backyard_01'],
    owner: 'A',
    why: 'A (S17 gate 1, POOL): its separation is PINNED to backyard_01\'s site data. Fly it '
       + 'elsewhere and the pin describes a night nobody plays.',
  },
  storm_02b_icenight: {
    sites: ['backyard_01'],
    owner: 'A',
    why: 'A (S17 gate 1, POOL), on A\'s S13 measurement: `gardenBeyondSaving` is a fact about '
       + 'THAT BED under that ice, not a property of the storm. Offered over another yard the '
       + 'night would carry the excuse without the evidence.',
  },
});

/**
 * May this storm be offered over this yard?
 * @returns {string|null} the refusal in English, or null when the pairing is offerable
 */
export function pairingRefusal(stormKey, siteKey) {
  const law = PAIRING_LAW[stormKey];
  if (!law || !law.sites) return null;
  if (law.sites.includes(siteKey)) return null;
  return `${stormKey} over ${siteKey}: not an offerable pairing — ${law.why} `
       + `(offerable: ${law.sites.join(', ')}; ruled by ${law.owner})`;
}

/**
 * Every pairing refusal in a list of candidate nights, as data.
 *
 * ⚠️ Deliberately NOT a filter. Silently dropping a bad entry leaves a morning
 * with one offer and no explanation — a runtime surprise wearing a fix's
 * clothes. The caller (c.test today; a `board.js` load-time assert the day A
 * wants one) decides how loud to be, and gets the measurement in the message.
 *
 * @param {Array<{id?:string, storm:string, site:string}>} pairings
 * @returns {{id:string, why:string}[]} empty = every pairing is offerable
 */
export function pairingRefusals(pairings = []) {
  const out = [];
  for (const p of pairings) {
    const why = pairingRefusal(p.storm, p.site);
    if (why) out.push({ id: p.id ?? `${p.storm}×${p.site}`, why });
  }
  return out;
}

// Resolved against this module, not the server root: server.py serves the repo
// root (so the 2D prototype stays reachable), but the demo bench serves web/.
// import.meta.url is right under both, and under whatever Lane A does next.
const STORM_DIR = new URL('../data/storms', import.meta.url).href;

/** Fetch + validate a storm def. Throws loud on bad data — storms are content. */
export async function loadStorm(name, dir = STORM_DIR) {
  const url = `${dir}/${name}.json`;
  const res = await fetch(url);
  if (!res.ok) throw new Error(`weather: cannot load ${url} (${res.status})`);
  const def = await res.json();
  const { ok, errors } = validateStorm(def, name);
  if (!ok) throw new Error(`weather: ${url} is invalid:\n  ${errors.join('\n  ')}`);
  return def;
}

/**
 * The wind a YARD actually flies — storm def + the SITE's local effects,
 * wired exactly as main.js does at every site load (setVenturi from
 * siteDef.wind.venturi, tree shelters from the anchors). SPRINT13:
 *
 * THREE harnesses have now measured site_02 with the funnel switched OFF by
 * building wind from the storm def alone — B's site_audit (Sprint 11, their
 * sweep.selftest tells the story), C's garden_bench (Sprint 13, where it
 * flipped the $80-line headline: 91.5 FULL funnel-off vs 39.8 TATTERED in
 * D's live replay), and probe4, which never attempted it. The venturi lives
 * in the SITE json, not the storm, so `def.wind.venturi` off a storm def
 * LOOKS right and never fires. Any tool measuring a yard builds its wind
 * HERE, or it is measuring a yard that doesn't ship. The strictly-raises
 * assert in c.test.js goes red if the setVenturi line is ever dropped.
 *
 * @param {object} stormDef  parsed storm JSON
 * @param {object} [siteDef] parsed site JSON (loadSite) — its wind.venturi list
 * @param {Array}  [anchors] world anchors; trees become wind shelters
 * @param {object} [opts]    forwarded to createWind ({seed})
 */
export function windForSite(stormDef, siteDef, anchors = [], opts = {}) {
  const wind = createWind(stormDef, opts);
  wind.setVenturi(siteDef?.wind?.venturi ?? []);
  wind.setSheltersFromTrees(anchors.filter((a) => a.type === 'tree'));
  return wind;
}

/**
 * @param {object} def   parsed storm JSON
 * @param {object} [opts] {seed} — same seed + same def = same storm, every run
 * @returns the `wind` object from contracts.js
 */
export function createWind(def, opts = {}) {
  const field = createWindField(def, opts);
  const scratch = { x: 0, y: 0, z: 0 };

  const wind = {
    /**
     * Wind velocity at a world position, m/s.
     * @param {THREE.Vector3} pos
     * @param {number} t              storm time, seconds
     * @param {THREE.Vector3} [out]   pass one to avoid allocating — sail.js
     *                                samples per-face per-frame, so this matters
     */
    sample(pos, t, out) {
      const v = out || new THREE.Vector3();
      field.vecAt(pos.x, pos.z, t, scratch);
      return v.set(scratch.x, scratch.y, scratch.z);
    },

    /** Scalar speed — for HUD, rain, grass. Cheaper than sample(); no allocation. */
    speedAt(pos, t) {
      return field.speedAt(pos.x, pos.z, t);
    },

    /** {eta, dir, power} while a gust is inbound but hasn't risen yet, else null. */
    gustTelegraph(t) {
      return field.telegraph(t);
    },

    /**
     * Register wind shadows (trees, house). Lane A: call after the yard is built.
     * Until then there are simply no shadows — nothing breaks.
     * @param {Array<{x,z,radius,strength,length}>} list
     */
    setShelters(list) { field.setShelters(list); return wind; },

    /** Convenience: take shadows straight off world.anchors' tree entries. */
    setSheltersFromTrees(trees, o = {}) {
      return wind.setShelters(trees.map((tr) => ({
        x: tr.pos ? tr.pos.x : tr.x,
        z: tr.pos ? tr.pos.z : tr.z,
        radius: o.radius ?? tr.radius ?? 3,
        strength: o.strength ?? 0.45,
        length: o.length ?? 14,
      })));
    },

    /**
     * A site's wind funnels (SPRINT9 site_02). Lane A: call with the site JSON's
     * `wind.venturi` after building the yard. Empty/absent = no funnels, so
     * backyard_01 reads exactly as it always has.
     * @param {Array<{x,z,axis,gain,radius,sharp}>} list
     */
    setVenturi(list) { field.setVenturi(list); return wind; },
    get venturi() { return field.venturi; },

    /** Storm events fired in (a,b] — poll with (t-dt, t). Deterministic. */
    eventsBetween(a, b) { return field.eventsBetween(a, b); },

    /** 0..1 rain intensity — drives drop count and opacity. */
    rainAt(t) { return field.rainAt(t); },

    /** 0..1 hail intensity (SPRINT5 decision 13). Zero for a hail-free storm. */
    hailAt(t) { return field.hailAt(t); },

    /** Stone-size scalar — audio pitch, visual scale, damage weight. */
    get hailSize() { return field.hailSize; },

    /** Rain rate in real-world mm/hr. Ponding (decision 10) reads this. */
    rainMmPerHour(t) { return field.rainMmPerHour(t); },

    /** Real-world mm of water delivered over (t0,t1]. Multiply by
     *  RAIN_TIME_COMPRESSION cloth-side — see weather.core. */
    rainDepthMm(t0, t1) { return field.rainDepthMm(t0, t1); },

    /** Direction (radians, XZ plane from +X toward +Z) ignoring local effects. */
    dirAt(t) { return field.dirAt(t); },

    get duration() { return field.duration; },
    get gusts() { return field.gusts; },
    get def() { return field.def; },
    get seed() { return field.seed; },
    core: field,
  };

  return wind;
}