fix

tests/test_yandex_ai.py

@@ -7,6 +7,7 @@ from assistant_bot.yandex_ai import (
     YandexAIClient,
     YandexSpeechRecognizer,
     describe_yandex_error,
+    prepare_chat_messages,
 )
 
 
@@ -38,6 +39,28 @@ class FakeChatCompletions:
 
 
 class YandexAIClientTests(unittest.IsolatedAsyncioTestCase):
+    def test_multiple_system_messages_are_merged_at_the_beginning(self) -> None:
+        self.assertEqual(
+            prepare_chat_messages(
+                [
+                    {"role": "system", "content": "Primary instructions"},
+                    {"role": "user", "content": "Earlier question"},
+                    {"role": "system", "content": "Runtime context"},
+                    {"role": "assistant", "content": "Earlier answer"},
+                    {"role": "user", "content": "Current question"},
+                ]
+            ),
+            [
+                {
+                    "role": "system",
+                    "content": "Primary instructions\n\nRuntime context",
+                },
+                {"role": "user", "content": "Earlier question"},
+                {"role": "assistant", "content": "Earlier answer"},
+                {"role": "user", "content": "Current question"},
+            ],
+        )
+
     def test_http_error_includes_safe_response_body(self) -> None:
         error = RuntimeError("forbidden")
         error.response = SimpleNamespace(