i18n(zh-CN): complete and ship Simplified Chinese

- Translate the remaining 910 strings and review the whole catalog (meaning,
  terms, punctuation, label length) against the screens.
- Register zh-CN: any zh tag maps to it except Traditional ones (Hant, TW,
  HK, MO), which keep English until a Traditional catalog ships.
- Hemisphere letters get their own context so the HUD sector line reads
  21.33N, not a compass word; the Bhote Koshi imagery dates follow
  year-first languages (2021年10月16日).
- cjk.css: tight tracking for Chinese text and a 9px floor on the dock voice
  labels and layer buttons; Latin HUD readouts keep their look.
- docs/translations/zh-CN.md: style, plurals and glossary.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/i18n/i18n.test.mjs

@@ -35,6 +35,12 @@ test('normalizeLocale folds regional variants and rejects unshipped tags', () =>
   assert.equal(normalizeLocale(' RU '), 'ru');
   assert.equal(normalizeLocale('en_GB'), 'en');
   assert.equal(normalizeLocale('xx'), null);
+  // Simplified Chinese by default; Traditional tags wait for zh-TW.
+  assert.equal(normalizeLocale('zh'), 'zh-CN');
+  assert.equal(normalizeLocale('zh-CN'), 'zh-CN');
+  assert.equal(normalizeLocale('zh-Hans-SG'), 'zh-CN');
+  assert.equal(normalizeLocale('zh-TW'), null);
+  assert.equal(normalizeLocale('zh-Hant-HK'), null);
   assert.equal(normalizeLocale(undefined), null);
 });
 

src/i18n/index.js

@@ -18,8 +18,9 @@ import {
 } from './locale.js';
 import es from './locales/es.json' with { type: 'json' };
 import ru from './locales/ru.json' with { type: 'json' };
+import zhCN from './locales/zh-CN.json' with { type: 'json' };
 
-const CATALOGS = Object.freeze({ es, ru });
+const CATALOGS = Object.freeze({ es, ru, 'zh-CN': zhCN });
 
 let currentLocale = DEFAULT_LOCALE;
 

src/i18n/locale.js

@@ -8,25 +8,32 @@ export const LOCALE_STORAGE_KEY = 'gev:locale:v1';
 export const DEFAULT_LOCALE = 'en';
 
 /** Shipped locales; order does not matter. Adding one: docs/TRANSLATORS.md. */
-export const LOCALES = Object.freeze(['en', 'es', 'ru']);
+export const LOCALES = Object.freeze(['en', 'es', 'ru', 'zh-CN']);
 
 /** Each locale named in its own language, for the selector. */
 export const LOCALE_NAMES = Object.freeze({
   en: 'English',
   es: 'Español',
   ru: 'Русский',
+  'zh-CN': '简体中文',
 });
 
 /** Right-to-left locales. */
 const RTL_LOCALES = Object.freeze([]);
 
 /**
- * Map any language tag to a shipped locale: 'ru-RU' and 'RU' → 'ru'.
+ * Map any language tag to a shipped locale: 'ru-RU' and 'RU' → 'ru',
+ * 'zh', 'zh-CN' and 'zh-Hans-SG' → 'zh-CN'.
  * @returns {string|null}
  */
 export function normalizeLocale(candidate) {
   if (typeof candidate !== 'string') return null;
-  const primary = candidate.trim().toLowerCase().split(/[-_]/)[0];
+  const [primary, ...rest] = candidate.trim().toLowerCase().split(/[-_]/);
+  // Traditional Chinese readers are not given Simplified: no zh-TW yet.
+  if (primary === 'zh')
+    return rest.some((part) => ['hant', 'tw', 'hk', 'mo'].includes(part))
+      ? null
+      : 'zh-CN';
   return LOCALES.includes(primary) ? primary : null;
 }
 

src/i18n/locales/es.json

@@ -1096,7 +1096,7 @@
   "FIELD REPORTS · {count}": "INFORMES DE CAMPO · {count}",
   "GEOLOCATIONS · {credit}": "GEOLOCALIZACIONES · {credit}",
   "↗ OPEN PUBLIC MAP": "↗ ABRIR MAPA PÚBLICO",
-  "Clouds are preserved from the source imagery.": "Las nubes provienen de las imágenes de origen.",
+  " Clouds are preserved from the source imagery.": " Las nubes provienen de las imágenes de origen.",
   "Show the Nepal context callout without a border or country fill": "Muestra la etiqueta de contexto de Nepal sin frontera ni relleno del país",
   "Introduce Nepal, draw its border, then reveal the Bhote Koshi incident": "Presenta Nepal, dibuja su frontera y luego revela el incidente del Bhote Koshi",
   "CITIES": "CIUDADES",
@@ -2890,5 +2890,9 @@
   "USB work abandoned after a stalled transfer": "Trabajo USB cancelado tras una transferencia bloqueada",
   "SDR decoder did not start; receiver stopped": "El decodificador SDR no arrancó; receptor detenido",
   "SDR decoder stopped responding; receiver stopped": "El decodificador SDR dejó de responder; receptor detenido",
-  "SDR decoder fell behind; receiver stopped": "El decodificador SDR se quedó atrás; receptor detenido"
+  "SDR decoder fell behind; receiver stopped": "El decodificador SDR se quedó atrás; receptor detenido",
+  "hemisphere|N": "N",
+  "hemisphere|S": "S",
+  "hemisphere|E": "E",
+  "hemisphere|W": "O"
 }

src/i18n/locales/ru.json

@@ -1110,7 +1110,7 @@
   "FIELD REPORTS · {count}": "СООБЩЕНИЯ С МЕСТА · {count}",
   "GEOLOCATIONS · {credit}": "ГЕОЛОКАЦИИ · {credit}",
   "↗ OPEN PUBLIC MAP": "↗ ОТКРЫТЬ ПУБЛИЧНУЮ КАРТУ",
-  "Clouds are preserved from the source imagery.": "Облака оставлены такими, как на исходных снимках.",
+  " Clouds are preserved from the source imagery.": " Облака оставлены такими, как на исходных снимках.",
   "Show the Nepal context callout without a border or country fill": "Показать выноску с контекстом Непала без границы и заливки страны",
   "Introduce Nepal, draw its border, then reveal the Bhote Koshi incident": "Представить Непал, нарисовать его границу, затем показать инцидент на Bhote Koshi",
   "CITIES": "ГОРОДА",
@@ -2957,5 +2957,9 @@
   "USB work abandoned after a stalled transfer": "Работа с USB прервана: передача данных зависла",
   "SDR decoder did not start; receiver stopped": "Декодер SDR не запустился; приёмник остановлен",
   "SDR decoder stopped responding; receiver stopped": "Декодер SDR перестал отвечать; приёмник остановлен",
-  "SDR decoder fell behind; receiver stopped": "Декодер SDR не успевает; приёмник остановлен"
+  "SDR decoder fell behind; receiver stopped": "Декодер SDR не успевает; приёмник остановлен",
+  "hemisphere|N": "С",
+  "hemisphere|S": "Ю",
+  "hemisphere|E": "В",
+  "hemisphere|W": "З"
 }

src/i18n/same-as-english.json

@@ -98,6 +98,9 @@
     "fire confidence|nominal",
     "ft",
     "hPa",
+    "hemisphere|E",
+    "hemisphere|N",
+    "hemisphere|S",
     "installation class|BASE",
     "km",
     "km/h",
@@ -133,5 +136,60 @@
     "REC",
     "VS",
     "WHOT/BHOT"
+  ],
+  "zh-CN": [
+    "1090 MHz",
+    "978 MHz UAT",
+    "AIS: --",
+    "AIS: {name}",
+    "BRG {value}°",
+    "BRG —",
+    "CAL {value}",
+    "CAL · {badge}",
+    "CCTV",
+    "CRS {value}°",
+    "CRT",
+    "FLIR",
+    "FOV",
+    "FOV {value}°",
+    "FT",
+    "GEO",
+    "HDG",
+    "HDG {value}°",
+    "House",
+    "Ironbow",
+    "KTS",
+    "Landsat 8/9",
+    "MM",
+    "NVG",
+    "REC",
+    "SRC {value}",
+    "Sentinel-2",
+    "Techno",
+    "Trance",
+    "USB {rate} msg/s",
+    "WHOT/BHOT",
+    "dB",
+    "ft",
+    "hPa",
+    "hemisphere|E",
+    "hemisphere|N",
+    "hemisphere|S",
+    "hemisphere|W",
+    "km",
+    "km/h",
+    "kt",
+    "kts",
+    "mph",
+    "{city} CCTV",
+    "{rate} msg/s",
+    "{source} HTTP {status}",
+    "{speed} kn",
+    "{type}  SPD: {speed}  HDG: {heading}",
+    "{value} KM",
+    "{value} KM/S",
+    "ΔE",
+    "ΔN",
+    "▲ {frp} MW"
   ]
 }