fix(tests): disable workflow cleanup in CI to preserve shared n8n instance

The cleanup was deleting ALL test workflows in CI, including the pre-activated
webhook workflow that needs to persist across test runs. Since CI uses a shared
n8n instance (not a disposable test instance), we should skip cleanup there.

Cleanup now only runs locally where users can recreate their own test workflows.

Critical fix: Prevents accidental deletion of the webhook workflow in CI

tests/integration/n8n-api/workflows/create-workflow.test.ts

@@ -36,8 +36,11 @@ describe('Integration: handleCreateWorkflow', () => {
 
   // Global cleanup after all tests to catch any orphaned workflows
   // (e.g., from test retries or failures)
+  // IMPORTANT: Skip cleanup in CI to preserve shared n8n instance workflows
   afterAll(async () => {
+    if (!process.env.CI) {
       await cleanupOrphanedWorkflows();
+    }
   });
 
   // ======================================================================