Normalize Brave search locale parameters

tests/test_web_search.py

@@ -38,6 +38,27 @@ class WebSearchTests(unittest.IsolatedAsyncioTestCase):
         with self.assertRaisesRegex(ValueError, "freshness"):
             build_query(AIWebSearchConfig(), {"query": "news", "freshness": "yesterday"})
 
+    def test_build_query_normalizes_unsupported_brave_country_and_ui_lang(self) -> None:
+        config = AIWebSearchConfig(
+            api_key="key",
+            country="UA",
+            search_lang="ru",
+            ui_lang="ru-UA",
+        )
+
+        query = build_query(config, {"query": "crimea news"})
+
+        self.assertEqual(query.country, "ALL")
+        self.assertEqual(query.search_lang, "ru")
+        self.assertEqual(query.ui_lang, "ru-RU")
+
+    def test_build_query_falls_back_unknown_ui_lang_to_english(self) -> None:
+        config = AIWebSearchConfig(api_key="key", ui_lang="zz-ZZ")
+
+        query = build_query(config, {"query": "python"})
+
+        self.assertEqual(query.ui_lang, "en-US")
+
     def test_parse_and_format_results(self) -> None:
         response = parse_response(
             "openai",