fix(radio): resolve common country exonyms Intl.DisplayNames omits (#232)

Recognize common country names and exonyms in Radio country requests and station filtering. Keep ambiguous country names rejected.

src/data/radioCountry.js

@@ -55,6 +55,22 @@ for (const [name, code] of Object.entries({
   brunei: 'BN',
   'cape verde': 'CV',
   'the netherlands': 'NL',
+  // Common English names and exonyms whose code is not reachable through the
+  // Intl.DisplayNames primary label, so they would otherwise fail closed
+  // (verified against ICU 77): TR resolves only as 'Türkiye', MM only as
+  // 'Myanmar (Burma)', AE only as 'United Arab Emirates', SZ as 'Eswatini',
+  // TL as 'Timor-Leste'. Each maps to exactly one country; ambiguous names
+  // (e.g. bare "Congo") are deliberately left to fail closed.
+  turkey: 'TR',
+  turkiye: 'TR',
+  myanmar: 'MM',
+  burma: 'MM',
+  uae: 'AE',
+  holland: 'NL',
+  swaziland: 'SZ',
+  'east timor': 'TL',
+  'cabo verde': 'CV',
+  vatican: 'VA',
 })) COUNTRY_NAME_TO_CODE.set(countryKey(name), code);
 
 function canonicalCountryName(code) {

src/data/radioCountry.test.mjs

@@ -18,6 +18,37 @@ test('Radio country normalization maps ISO codes and bounded common names', () =
   }
 });
 
+test('Radio country normalization resolves common English names/exonyms ICU misses', () => {
+  // Each of these fails closed against the Intl.DisplayNames primary label
+  // alone (e.g. TR is "Türkiye", MM is "Myanmar (Burma)", AE is "United Arab
+  // Emirates"), so a request like "play radio in Turkey" would return nothing.
+  for (const [input, code] of [
+    ['Turkey', 'TR'],
+    ['Turkiye', 'TR'],
+    ['Myanmar', 'MM'],
+    ['Burma', 'MM'],
+    ['UAE', 'AE'],
+    ['U.A.E.', 'AE'],
+    ['Holland', 'NL'],
+    ['Swaziland', 'SZ'],
+    ['East Timor', 'TL'],
+    ['Cabo Verde', 'CV'],
+    ['Vatican', 'VA'],
+  ]) {
+    const result = normalizeRadioCountryInput(input);
+    assert.equal(result.valid, true, input);
+    assert.equal(result.code, code, input);
+  }
+});
+
+test('Ambiguous country names still fail closed (no broadened selection)', () => {
+  // Two states share the name "Congo" (CD/CG), so a bare mention must not
+  // resolve to either — it stays low-confidence and fails closed.
+  for (const input of ['Congo', 'Korea']) {
+    assert.equal(normalizeRadioCountryInput(input).valid, false, input);
+  }
+});
+
 test('Radio country normalization rejects malformed, non-ISO, and oversized values', () => {
   for (const input of [
     'ZZ',