refactor: replace runtime Intl.DisplayNames with a static CLDR-generated country table

- Add `scripts/generate-countries.mjs` to enumerate all current ISO 3166-1 alpha-2 codes via CLDR and emit `src/lib/countries-data.ts`; retired, exceptionally-reserved, and CLDR-only pseudo codes are explicitly excluded, XK (Kosovo) is kept
- Replace the live `Intl.DisplayNames` calls in `countries.ts` with a direct lookup against the generated `COUNTRY_NAMES` record, eliminating variance between Node/ICU versions
- Build the reverse `nameToCode` map from `COUNTRY_NAMES` entries instead of a double-nested loop over the alphabet
- Fix `countryCodeFromName` to fall through to `ALIASES` for two-letter inputs that aren't valid codes (e.g. `"UK"` → `"GB"`)
- Add `myanmar` / `"myanmar burma"` aliases so the CLDR-style name and the legacy WHOIS variant both resolve to `MM`
- Extend `countries.test.ts` to assert pinned names, XK presence, retired/reserved code exclusion, and `UK` alias behaviour

scripts/generate-countries.mjs

@@ -0,0 +1,64 @@
+// Regenerates src/lib/countries-data.ts from the local runtime's ICU (CLDR) region names.
+// Usage: node scripts/generate-countries.mjs
+import { writeFileSync } from "node:fs";
+
+const dn = new Intl.DisplayNames(["en"], { type: "region" });
+// CLDR also knows reserved, retired and pseudo codes that aren't current ISO 3166-1 countries.
+// Keep only current ISO 3166-1 alpha-2 codes plus XK (Kosovo, the de-facto user-assigned code).
+const EXCLUDE = new Set([
+  "AC",
+  "CP",
+  "DG",
+  "EA",
+  "EU",
+  "EZ",
+  "IC",
+  "TA",
+  "UN", // exceptionally reserved
+  "AN",
+  "BU",
+  "CQ",
+  "CS",
+  "DD",
+  "DY",
+  "FX",
+  "HV",
+  "NH",
+  "RH",
+  "SU",
+  "TP",
+  "VD",
+  "YD",
+  "YU",
+  "ZR", // retired
+  "UK", // reserved for GB; WHOIS "UK" is handled as an alias in countries.ts
+  "QO",
+  "XA",
+  "XB", // CLDR-only pseudo territories
+]);
+
+const entries = [];
+for (let a = 65; a <= 90; a++) {
+  for (let b = 65; b <= 90; b++) {
+    const code = String.fromCharCode(a, b);
+    if (EXCLUDE.has(code)) continue;
+    let name;
+    try {
+      name = dn.of(code);
+    } catch {
+      continue;
+    }
+    if (!name || name === code || name === "Unknown Region") continue;
+    entries.push([code, name]);
+  }
+}
+
+const body = entries.map(([c, n]) => `  ${c}: ${JSON.stringify(n)},`).join("\n");
+writeFileSync(
+  new URL("../src/lib/countries-data.ts", import.meta.url),
+  `// Generated by scripts/generate-countries.mjs from CLDR (Unicode license). Do not edit by hand.\n` +
+    `export const COUNTRY_NAMES: Record<string, string> = {\n${body}\n};\n`,
+);
+console.log(
+  `Wrote ${entries.length} countries (Node ${process.version}, ICU ${process.versions.icu}, CLDR ${process.versions.cldr})`,
+);

src/lib/countries-data.ts

@@ -0,0 +1,253 @@
+// Generated by scripts/generate-countries.mjs from CLDR (Unicode license). Do not edit by hand.
+export const COUNTRY_NAMES: Record<string, string> = {
+  AD: "Andorra",
+  AE: "United Arab Emirates",
+  AF: "Afghanistan",
+  AG: "Antigua & Barbuda",
+  AI: "Anguilla",
+  AL: "Albania",
+  AM: "Armenia",
+  AO: "Angola",
+  AQ: "Antarctica",
+  AR: "Argentina",
+  AS: "American Samoa",
+  AT: "Austria",
+  AU: "Australia",
+  AW: "Aruba",
+  AX: "Åland Islands",
+  AZ: "Azerbaijan",
+  BA: "Bosnia & Herzegovina",
+  BB: "Barbados",
+  BD: "Bangladesh",
+  BE: "Belgium",
+  BF: "Burkina Faso",
+  BG: "Bulgaria",
+  BH: "Bahrain",
+  BI: "Burundi",
+  BJ: "Benin",
+  BL: "St. Barthélemy",
+  BM: "Bermuda",
+  BN: "Brunei",
+  BO: "Bolivia",
+  BQ: "Caribbean Netherlands",
+  BR: "Brazil",
+  BS: "Bahamas",
+  BT: "Bhutan",
+  BV: "Bouvet Island",
+  BW: "Botswana",
+  BY: "Belarus",
+  BZ: "Belize",
+  CA: "Canada",
+  CC: "Cocos (Keeling) Islands",
+  CD: "Congo - Kinshasa",
+  CF: "Central African Republic",
+  CG: "Congo - Brazzaville",
+  CH: "Switzerland",
+  CI: "Côte d’Ivoire",
+  CK: "Cook Islands",
+  CL: "Chile",
+  CM: "Cameroon",
+  CN: "China",
+  CO: "Colombia",
+  CR: "Costa Rica",
+  CU: "Cuba",
+  CV: "Cape Verde",
+  CW: "Curaçao",
+  CX: "Christmas Island",
+  CY: "Cyprus",
+  CZ: "Czechia",
+  DE: "Germany",
+  DJ: "Djibouti",
+  DK: "Denmark",
+  DM: "Dominica",
+  DO: "Dominican Republic",
+  DZ: "Algeria",
+  EC: "Ecuador",
+  EE: "Estonia",
+  EG: "Egypt",
+  EH: "Western Sahara",
+  ER: "Eritrea",
+  ES: "Spain",
+  ET: "Ethiopia",
+  FI: "Finland",
+  FJ: "Fiji",
+  FK: "Falkland Islands",
+  FM: "Micronesia",
+  FO: "Faroe Islands",
+  FR: "France",
+  GA: "Gabon",
+  GB: "United Kingdom",
+  GD: "Grenada",
+  GE: "Georgia",
+  GF: "French Guiana",
+  GG: "Guernsey",
+  GH: "Ghana",
+  GI: "Gibraltar",
+  GL: "Greenland",
+  GM: "Gambia",
+  GN: "Guinea",
+  GP: "Guadeloupe",
+  GQ: "Equatorial Guinea",
+  GR: "Greece",
+  GS: "South Georgia & South Sandwich Islands",
+  GT: "Guatemala",
+  GU: "Guam",
+  GW: "Guinea-Bissau",
+  GY: "Guyana",
+  HK: "Hong Kong SAR China",
+  HM: "Heard & McDonald Islands",
+  HN: "Honduras",
+  HR: "Croatia",
+  HT: "Haiti",
+  HU: "Hungary",
+  ID: "Indonesia",
+  IE: "Ireland",
+  IL: "Israel",
+  IM: "Isle of Man",
+  IN: "India",
+  IO: "British Indian Ocean Territory",
+  IQ: "Iraq",
+  IR: "Iran",
+  IS: "Iceland",
+  IT: "Italy",
+  JE: "Jersey",
+  JM: "Jamaica",
+  JO: "Jordan",
+  JP: "Japan",
+  KE: "Kenya",
+  KG: "Kyrgyzstan",
+  KH: "Cambodia",
+  KI: "Kiribati",
+  KM: "Comoros",
+  KN: "St. Kitts & Nevis",
+  KP: "North Korea",
+  KR: "South Korea",
+  KW: "Kuwait",
+  KY: "Cayman Islands",
+  KZ: "Kazakhstan",
+  LA: "Laos",
+  LB: "Lebanon",
+  LC: "St. Lucia",
+  LI: "Liechtenstein",
+  LK: "Sri Lanka",
+  LR: "Liberia",
+  LS: "Lesotho",
+  LT: "Lithuania",
+  LU: "Luxembourg",
+  LV: "Latvia",
+  LY: "Libya",
+  MA: "Morocco",
+  MC: "Monaco",
+  MD: "Moldova",
+  ME: "Montenegro",
+  MF: "St. Martin",
+  MG: "Madagascar",
+  MH: "Marshall Islands",
+  MK: "North Macedonia",
+  ML: "Mali",
+  MM: "Myanmar (Burma)",
+  MN: "Mongolia",
+  MO: "Macao SAR China",
+  MP: "Northern Mariana Islands",
+  MQ: "Martinique",
+  MR: "Mauritania",
+  MS: "Montserrat",
+  MT: "Malta",
+  MU: "Mauritius",
+  MV: "Maldives",
+  MW: "Malawi",
+  MX: "Mexico",
+  MY: "Malaysia",
+  MZ: "Mozambique",
+  NA: "Namibia",
+  NC: "New Caledonia",
+  NE: "Niger",
+  NF: "Norfolk Island",
+  NG: "Nigeria",
+  NI: "Nicaragua",
+  NL: "Netherlands",
+  NO: "Norway",
+  NP: "Nepal",
+  NR: "Nauru",
+  NU: "Niue",
+  NZ: "New Zealand",
+  OM: "Oman",
+  PA: "Panama",
+  PE: "Peru",
+  PF: "French Polynesia",
+  PG: "Papua New Guinea",
+  PH: "Philippines",
+  PK: "Pakistan",
+  PL: "Poland",
+  PM: "St. Pierre & Miquelon",
+  PN: "Pitcairn Islands",
+  PR: "Puerto Rico",
+  PS: "Palestinian Territories",
+  PT: "Portugal",
+  PW: "Palau",
+  PY: "Paraguay",
+  QA: "Qatar",
+  RE: "Réunion",
+  RO: "Romania",
+  RS: "Serbia",
+  RU: "Russia",
+  RW: "Rwanda",
+  SA: "Saudi Arabia",
+  SB: "Solomon Islands",
+  SC: "Seychelles",
+  SD: "Sudan",
+  SE: "Sweden",
+  SG: "Singapore",
+  SH: "St. Helena",
+  SI: "Slovenia",
+  SJ: "Svalbard & Jan Mayen",
+  SK: "Slovakia",
+  SL: "Sierra Leone",
+  SM: "San Marino",
+  SN: "Senegal",
+  SO: "Somalia",
+  SR: "Suriname",
+  SS: "South Sudan",
+  ST: "São Tomé & Príncipe",
+  SV: "El Salvador",
+  SX: "Sint Maarten",
+  SY: "Syria",
+  SZ: "Eswatini",
+  TC: "Turks & Caicos Islands",
+  TD: "Chad",
+  TF: "French Southern Territories",
+  TG: "Togo",
+  TH: "Thailand",
+  TJ: "Tajikistan",
+  TK: "Tokelau",
+  TL: "Timor-Leste",
+  TM: "Turkmenistan",
+  TN: "Tunisia",
+  TO: "Tonga",
+  TR: "Türkiye",
+  TT: "Trinidad & Tobago",
+  TV: "Tuvalu",
+  TW: "Taiwan",
+  TZ: "Tanzania",
+  UA: "Ukraine",
+  UG: "Uganda",
+  UM: "U.S. Outlying Islands",
+  US: "United States",
+  UY: "Uruguay",
+  UZ: "Uzbekistan",
+  VA: "Vatican City",
+  VC: "St. Vincent & Grenadines",
+  VE: "Venezuela",
+  VG: "British Virgin Islands",
+  VI: "U.S. Virgin Islands",
+  VN: "Vietnam",
+  VU: "Vanuatu",
+  WF: "Wallis & Futuna",
+  WS: "Samoa",
+  XK: "Kosovo",
+  YE: "Yemen",
+  YT: "Mayotte",
+  ZA: "South Africa",
+  ZM: "Zambia",
+  ZW: "Zimbabwe",
+};

src/lib/countries.test.ts

@@ -19,3 +19,12 @@ test("resolveCountry fills whichever side is missing", () => {
     countryCode: undefined,
   });
 });
+
+test("static table: pinned names, XK kept, retired/reserved codes excluded, UK is GB", () => {
+  expect(countryNameFromCode("XK")).toBe("Kosovo");
+  expect(countryNameFromCode("SU")).toBeUndefined();
+  expect(countryNameFromCode("UK")).toBeUndefined();
+  expect(countryCodeFromName("UK")).toBe("GB");
+  expect(countryCodeFromName("Myanmar")).toBe("MM");
+  expect(resolveCountry("UK", undefined)).toEqual({ country: "United Kingdom", countryCode: "GB" });
+});

src/lib/countries.ts

@@ -1,4 +1,6 @@
-// Country name <-> ISO 3166-1 alpha-2 resolution, backed by the runtime's ICU data.
+// Country name <-> ISO 3166-1 alpha-2 resolution, backed by a static table (see
+// scripts/generate-countries.mjs) so results don't vary with the runtime's ICU version.
+import { COUNTRY_NAMES } from "./countries-data";
 
 const ALIASES: Record<string, string> = {
   usa: "US",
@@ -32,6 +34,8 @@ const ALIASES: Record<string, string> = {
   holland: "NL",
   uae: "AE",
   burma: "MM",
+  myanmar: "MM",
+  "myanmar burma": "MM",
   "ivory coast": "CI",
   "cote d'ivoire": "CI",
   laos: "LA",
@@ -51,45 +55,24 @@ const normalize = (s: string) =>
     .replace(/\s+/g, " ")
     .trim();
 
-let displayNames: Intl.DisplayNames | undefined;
 let nameToCode: Map<string, string> | undefined;
 
-function getDisplayNames(): Intl.DisplayNames | undefined {
-  if (displayNames) return displayNames;
-  try {
-    displayNames = new Intl.DisplayNames(["en"], { type: "region" });
-  } catch {
-    // Runtime without Intl.DisplayNames support
-  }
-  return displayNames;
-}
-
 /** English country name for an ISO 3166-1 alpha-2 code, or undefined if unknown. */
 export function countryNameFromCode(code: string): string | undefined {
-  const c = code.trim().toUpperCase();
+  return COUNTRY_NAMES[code.trim().toUpperCase()];
-  if (!/^[A-Z]{2}$/.test(c)) return undefined;
-  try {
-    const name = getDisplayNames()?.of(c);
-    return name && name !== c && name !== "Unknown Region" ? name : undefined;
-  } catch {
-    return undefined;
-  }
 }
 
 /** ISO 3166-1 alpha-2 code for a country name (or the code itself), or undefined if unknown. */
 export function countryCodeFromName(value: string): string | undefined {
   const v = value.trim();
   if (!v) return undefined;
-  if (/^[A-Za-z]{2}$/.test(v)) return countryNameFromCode(v) ? v.toUpperCase() : undefined;
+  if (/^[A-Za-z]{2}$/.test(v)) {
+    return countryNameFromCode(v) ? v.toUpperCase() : ALIASES[v.toLowerCase()];
+  }
   if (!nameToCode) {
-    nameToCode = new Map();
+    nameToCode = new Map(
-    for (let a = 65; a <= 90; a++) {
+      Object.entries(COUNTRY_NAMES).map(([code, name]) => [normalize(name), code]),
-      for (let b = 65; b <= 90; b++) {
+    );
-        const code = String.fromCharCode(a, b);
-        const name = countryNameFromCode(code);
-        if (name) nameToCode.set(normalize(name), code);
-      }
-    }
   }
   const key = normalize(v);
   return nameToCode.get(key) ?? ALIASES[key];