fix(users): harden google oauth account resolution

core/exceptions/handlers.py

@@ -15,6 +15,26 @@ from rest_framework.views import exception_handler as drf_exception_handler
 logger = logging.getLogger(__name__)
 
 
+def _extract_code(value: Any) -> str | None:
+    if isinstance(value, ErrorDetail):
+        return str(value.code) if getattr(value, "code", None) else None
+    if isinstance(value, list | tuple):
+        for item in value:
+            code = _extract_code(item)
+            if code:
+                return code
+        return None
+    if isinstance(value, dict):
+        for item in value.values():
+            code = _extract_code(item)
+            if code:
+                return code
+        return None
+    if isinstance(value, str):
+        return None
+    return getattr(value, "code", None)
+
+
 def _flatten_messages(values: Iterable) -> list[str]:
     items: list[str] = []
     for value in values:
@@ -107,6 +127,13 @@ def exception_handler(exc, context) -> Response:
                         else None,
                     }
                 )
+            else:
+                code = _extract_code(detail)
+                if code:
+                    payload["code"] = code
+                extra_payload = getattr(exc, "payload_extra", None)
+                if isinstance(extra_payload, dict):
+                    payload.update(extra_payload)
             formatted_response = Response(payload, status=status_code)
             for header, value in response.headers.items():
                 formatted_response[header] = value