fix(ops): English replies from English prompts and ROLE_SYSTEM.en

Detect language from user message before UI hint, load ops ROLE_SYSTEM.en.md when en, and wire user_text through WS/HTTP/worker paths.

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

tests/test_resolve_runtime_lang.py

@@ -1,11 +1,23 @@
 import unittest
 from unittest import mock
 
-from runtime.lang import resolve_runtime_lang
+from runtime.lang import detect_text_lang, resolve_runtime_lang
 
 
 class ResolveRuntimeLangTests(unittest.TestCase):
-    def test_hint_wins(self) -> None:
+    def test_user_text_english_overrides_ui_zh(self) -> None:
+        store = mock.Mock()
+        store.get_setting.return_value = "zh"
+        self.assertEqual(
+            resolve_runtime_lang(
+                store=store,
+                hint="zh",
+                user_text="Please tally the current alarm information",
+            ),
+            "en",
+        )
+
+    def test_hint_when_text_ambiguous(self) -> None:
         store = mock.Mock()
         store.get_setting.return_value = "zh"
         self.assertEqual(resolve_runtime_lang(store=store, hint="en"), "en")
@@ -20,6 +32,12 @@ class ResolveRuntimeLangTests(unittest.TestCase):
         store.get_setting.return_value = "fr"
         self.assertEqual(resolve_runtime_lang(store=store), "zh")
 
+    def test_detect_english(self) -> None:
+        self.assertEqual(detect_text_lang("Please tally alarms"), "en")
+
+    def test_detect_chinese(self) -> None:
+        self.assertEqual(detect_text_lang("请统计当前告警信息"), "zh")
+
 
 if __name__ == "__main__":
     unittest.main()