fix(chat): honor ui_lang on WebSocket turns; ops NE display by host_name

Resolve runtime language from ui_lang and chat.send lang instead of hardcoding zh.
Align generalist/ops prompts with user language and require host_name (not ne_id) in ops outputs.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_resolve_runtime_lang.py

@@ -0,0 +1,25 @@
+import unittest
+from unittest import mock
+
+from runtime.lang import resolve_runtime_lang
+
+
+class ResolveRuntimeLangTests(unittest.TestCase):
+    def test_hint_wins(self) -> None:
+        store = mock.Mock()
+        store.get_setting.return_value = "zh"
+        self.assertEqual(resolve_runtime_lang(store=store, hint="en"), "en")
+
+    def test_store_ui_lang(self) -> None:
+        store = mock.Mock()
+        store.get_setting.return_value = "en"
+        self.assertEqual(resolve_runtime_lang(store=store), "en")
+
+    def test_invalid_falls_back_zh(self) -> None:
+        store = mock.Mock()
+        store.get_setting.return_value = "fr"
+        self.assertEqual(resolve_runtime_lang(store=store), "zh")
+
+
+if __name__ == "__main__":
+    unittest.main()