landing: harden GOA alt display for all three sites

Ship goa-amount.js inside each landing tree, add an inline fallback when
the asset is not yet deployed, keep CHF free of GOA unit names, fix
exchange amount_full wiring, and add test-landing-stats.sh (local + live).

configs/exchange-landing/goa-amount.js

@@ -0,0 +1,169 @@
+/* Compact GOA / CUR:amount display using currency alt_unit_names.
+ * Large values → "1.23 Mega-GOA" (title = full GOA:n) so landing tiles fit.
+ */
+(function (global) {
+  "use strict";
+
+  var DEFAULT_ALT = {
+    "24": "Yotta-GOA",
+    "21": "Zetta-GOA",
+    "18": "Exa-GOA",
+    "15": "Peta-GOA",
+    "12": "Tera-GOA",
+    "9": "Giga-GOA",
+    "6": "Mega-GOA",
+    "3": "Kilo-GOA",
+    "0": "GOA",
+    "-1": "Deci-GOA",
+    "-2": "Centi-GOA",
+    "-3": "Milli-GOA",
+    "-6": "Micro-GOA",
+    "-7": "Deci-Micro-GOA",
+    "-8": "Atomic-GOA"
+  };
+
+  var THRESHOLD = 1000;
+
+  function parseAmount(s) {
+    if (s == null || s === "") return { cur: "GOA", val: 0 };
+    if (typeof s === "number") return { cur: "GOA", val: s };
+    var t = String(s).trim();
+    var i = t.indexOf(":");
+    if (i < 0) return { cur: "GOA", val: parseFloat(t) || 0 };
+    return {
+      cur: t.slice(0, i) || "GOA",
+      val: parseFloat(t.slice(i + 1)) || 0
+    };
+  }
+
+  function fmtCoeff(v) {
+    if (!isFinite(v)) return "?";
+    var a = Math.abs(v);
+    if (Math.abs(a - Math.round(a)) < 1e-9) return String(Math.round(v));
+    var s = v.toFixed(4).replace(/\.?0+$/, "");
+    return s;
+  }
+
+  function baseStr(cur, val) {
+    if (!isFinite(val)) return String(cur) + ":?";
+    if (Math.abs(val - Math.round(val)) < 1e-9) return cur + ":" + Math.round(val);
+    return cur + ":" + String(val).replace(/(\.\d*?[1-9])0+$/, "$1").replace(/\.0+$/, "");
+  }
+
+  /**
+   * @param {string|number} amount
+   * @param {object} [altMap]
+   * @returns {{ display: string, title: string, raw: string, usedAlt: boolean }}
+   */
+  function format(amount, altMap) {
+    if (amount == null || amount === "") {
+      return { display: "—", title: "", raw: "", usedAlt: false };
+    }
+    // Prefer server-provided alt if caller passes object {amount, amount_alt}
+    if (typeof amount === "object" && amount) {
+      if (amount.amount_alt) {
+        var rawO = amount.amount || amount.amount_full || String(amount.amount_alt);
+        return {
+          display: String(amount.amount_alt),
+          title: amount.amount_full || rawO,
+          raw: String(rawO),
+          usedAlt: true
+        };
+      }
+      amount = amount.amount || amount.amount_full || "";
+    }
+
+    var alt = altMap || global.__GOA_ALT_UNITS || DEFAULT_ALT;
+    var p = parseAmount(amount);
+    var raw = baseStr(p.cur, p.val);
+    // Foreign currencies must not pick up Kilo-GOA / Mega-GOA labels
+    var baseName = (alt && alt["0"]) || p.cur;
+    var curU = String(p.cur || "").toUpperCase();
+    var baseU = String(baseName || "").toUpperCase();
+    if (curU && curU !== "GOA" && (baseU === "GOA" || baseU.indexOf("GOA") !== -1)) {
+      return { display: raw, title: raw, raw: raw, usedAlt: false };
+    }
+    if (p.val === 0) {
+      return { display: raw, title: raw, raw: raw, usedAlt: false };
+    }
+    if (Math.abs(p.val) < THRESHOLD) {
+      return { display: raw, title: raw, raw: raw, usedAlt: false };
+    }
+
+    var scales = [];
+    Object.keys(alt || {}).forEach(function (k) {
+      var n = parseInt(k, 10);
+      if (!isNaN(n)) scales.push({ sc: n, name: String(alt[k]) });
+    });
+    scales.sort(function (a, b) { return b.sc - a.sc; });
+
+    var abs = Math.abs(p.val);
+    var chosen = null;
+    for (var i = 0; i < scales.length; i++) {
+      var unit = Math.pow(10, scales[i].sc);
+      if (!(unit > 0)) continue;
+      var coeff = abs / unit;
+      if (coeff >= 1) {
+        chosen = {
+          sc: scales[i].sc,
+          name: scales[i].name,
+          coeff: p.val >= 0 ? coeff : -coeff
+        };
+        break;
+      }
+    }
+    if (!chosen || chosen.sc === 0) {
+      return { display: raw, title: raw, raw: raw, usedAlt: false };
+    }
+    var short = fmtCoeff(chosen.coeff) + " " + chosen.name;
+    return {
+      display: short,
+      title: short + " (" + raw + ")",
+      raw: raw,
+      usedAlt: true
+    };
+  }
+
+  function setText(el, amount, altMap) {
+    if (!el) return;
+    var f = format(amount, altMap);
+    el.textContent = f.display;
+    if (f.title && f.title !== f.display) el.setAttribute("title", f.title);
+    else el.removeAttribute("title");
+  }
+
+  function setById(id, amount, altMap) {
+    setText(document.getElementById(id), amount, altMap);
+  }
+
+  /** Prefer amount_alt from stats row, else format amount. */
+  function pick(rowOrAmount, altMap) {
+    if (rowOrAmount && typeof rowOrAmount === "object") {
+      if (rowOrAmount.amount_alt) {
+        return format({
+          amount: rowOrAmount.amount,
+          amount_alt: rowOrAmount.amount_alt,
+          amount_full: rowOrAmount.amount_full
+        }, altMap);
+      }
+      return format(rowOrAmount.amount || rowOrAmount.total_amount, altMap);
+    }
+    return format(rowOrAmount, altMap);
+  }
+
+  function rememberAlt(stats) {
+    if (stats && stats.alt_unit_names && typeof stats.alt_unit_names === "object") {
+      global.__GOA_ALT_UNITS = stats.alt_unit_names;
+    }
+  }
+
+  global.GoaAmount = {
+    format: format,
+    setText: setText,
+    setById: setById,
+    pick: pick,
+    rememberAlt: rememberAlt,
+    DEFAULT_ALT: DEFAULT_ALT,
+    THRESHOLD: THRESHOLD
+  };
+})(typeof window !== "undefined" ? window : globalThis);