fix: address code review feedback - add descriptor count assertion and use fixed timestamp

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

packages/spec/src/automation/node-executor.test.ts

@@ -242,7 +242,7 @@ describe('Wait Executor — pause/resume scenario', () => {
         comments: 'All checks passed',
       },
       resumedBy: 'webhook_service',
-      resumedAt: new Date().toISOString(),
+      resumedAt: '2026-02-22T14:00:00Z',
       variables: {
         approval_status: 'approved',
       },

packages/spec/src/studio/flow-builder.test.ts

@@ -243,6 +243,7 @@ describe('BUILT_IN_NODE_DESCRIPTORS', () => {
     expect(actions).toContain('loop');
     expect(actions).toContain('subflow');
     expect(actions).toContain('connector_action');
+    expect(BUILT_IN_NODE_DESCRIPTORS).toHaveLength(18);
   });
 
   it('should validate all built-in descriptors against schema', () => {