refactor: replace overloaded surface terminology

packages/workflow/workflow/tests/workflow.spec.ts

@@ -123,7 +123,7 @@ describe('dsh-workflow (interface)', () => {
     expect(String(warn.mock.calls[0]![0])).toContain('[unrenderable thrown value]')
   })
 
-  it('has the expected export surface (default = the abstract service class)', () => {
+  it('has the expected exports (default = the abstract service class)', () => {
     expect(WorkflowServiceDefault).toBe(WorkflowService)
   })
 })