CI fails because handlers-manage-datatable.test.ts and handlers-n8n-manager.test.ts
share the same Vitest worker and module cache. The manage-datatable test mocks
N8nApiClient with 20 methods but handlers-n8n-manager only had 10. When running
in parallel, the singleton client state leaked between files causing mock mismatches.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>