Improve SMB credential handling for AI structure

services/api-server/tests/test_api.py

@@ -1310,6 +1310,28 @@ def test_server_smb_browse_validates_unc_path():
     assert "UNC путь" in response.json()["error"]
 
 
+def test_smb_credentials_embedded_domain_format_is_normalized():
+    from api_server import smb_paths
+
+    domain, username = smb_paths._normalize_credentials("MST\\m", None)
+
+    assert domain == "MST"
+    assert username == "m"
+
+
+def test_smb_error_translation_returns_russian_auth_message():
+    from api_server import smb_paths
+
+    message = smb_paths._translate_smb_error(
+        RuntimeError("STATUS_LOGON_FAILURE: logon failure"),
+        server="192.168.220.200",
+        username="MST\\m",
+    )
+
+    assert "Ошибка авторизации SMB" in message
+    assert "Проверьте логин, пароль, домен" in message
+
+
 def test_project_setup_recovers_indexed_status_from_stored_snapshot(tmp_path: Path):
     (tmp_path / "metadata.xml").write_text(
         """