chore: sync with upstream openapi.json

CHANGELOG.md

@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- Synced with the latest OpenAPI spec: `ListEmailsResponse` and
+  `ListProjectsResponse` no longer carry a top-level `success` flag;
+  `ErrorCode` gained `retrieval_error`, `insufficient_scope`, and
+  `schedule_cancellation_failed`; the webhook event-type typo
+  `engagament.*` was corrected to `engagement.*`. No SDK behavior
+  change — `error_code` values and webhook `events` strings continue
+  to accept any value, so callers don't need to update their code.
+
 ### Fixed
 - `emails.list()`, `emails.get()`, and `emails.list_events()` were reading
   responses at the wrong nesting level and silently returned empty results

tests/test_emails.py

@@ -168,7 +168,6 @@ def test_list_regression_nested_events_wrapper(
         empty list when the API actually had emails.
         """
         mock_client.get.return_value = {
-            "success": True,
             "message": "Emails retrieved successfully.",
             "data": {
                 "events": {