i18n(uk): complete and ship Ukrainian

- Translate the remaining 1,895 strings for the current UI (Bhote Koshi
  event, weather, imagery, street level, directions, SDR, voice, scenes,
  import) and review meirm's 832 entries from #312: 134 edited for
  Ukrainian HUD terms (КУРС/ПЕЛ./ШЛЯХ/ПРИЗН., Л/П, ОНЛАЙН for LIVE,
  Cyrillic units КМ, ВУЗ, ФТ, МВт), vessel types, number agreement and
  the ʼ apostrophe throughout.
- Register uk: catalog, LOCALES, LOCALE_NAMES (Українська), package
  boundaries, same-as-English codes; picker and plural tests cover the
  four Ukrainian forms.
- docs/translations/uk.md: style, plurals, units and glossary.

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

src/i18n/i18n.test.mjs

@@ -33,6 +33,8 @@ function memoryStorage(initial = {}) {
 test('normalizeLocale folds regional variants and rejects unshipped tags', () => {
   assert.equal(normalizeLocale('ru-RU'), 'ru');
   assert.equal(normalizeLocale(' RU '), 'ru');
+  assert.equal(normalizeLocale('uk'), 'uk');
+  assert.equal(normalizeLocale('uk-UA'), 'uk');
   assert.equal(normalizeLocale('en_GB'), 'en');
   assert.equal(normalizeLocale('xx'), null);
   // Explicit script tags take precedence over regional defaults.
@@ -142,6 +144,22 @@ test('tn() picks English and Russian plural forms', () => {
   assert.match(label(21), / 21 КЛЮЧ(?![А-ЯЁ])/);
 });
 
+test('tn() picks the four Ukrainian plural forms', () => {
+  const label = (count) =>
+    tn(
+      count,
+      'POWER UP · {count} KEY WAITING',
+      'POWER UP · {count} KEYS WAITING',
+    );
+  setLocale('uk');
+  assert.match(label(1), / 1 КЛЮЧ(?![А-ЯҐЄІЇ])/);
+  assert.match(label(3), / 3 КЛЮЧІ(?![А-ЯҐЄІЇ])/);
+  assert.match(label(5), / 5 КЛЮЧІВ(?![А-ЯҐЄІЇ])/);
+  assert.match(label(11), / 11 КЛЮЧІВ(?![А-ЯҐЄІЇ])/);
+  assert.match(label(21), / 21 КЛЮЧ(?![А-ЯҐЄІЇ])/);
+  assert.match(label(1.5), / 1\.5 КЛЮЧА(?![А-ЯҐЄІЇ])/);
+});
+
 test('t() context separates identical English with different meanings', () => {
   assert.equal(t('CLEAR', { context: 'action' }), 'CLEAR');
   setLocale('ru');