Add step.verifiablePresentation option to explicitly express VP to be used in a step

index.html

@@ -2242,6 +2242,19 @@ <h4>Create Workflow</h4>
 }
         </pre>
 
+        <p>
+A step MAY inlcude a `verifiablePresentation` to explicitly express a
+[=verifiable presentation=] to be used in that step. This presentation could be
+composed via other variables in an exchange and can be augmented with any
+additional [=verifiable credentials=] that might be issued during the step (per
+`issueRequests`). This supports use cases where specific
+[=verifiable presentation=] versions are required, specific sub-types of
+[=verifiable presentations=] are required, or specific
+[=verifiable presentation=] contents are required, including previously
+out-of-band issued [=verifiable credentials=] that are to be delivered in the
+workflow step.
+        </p>
+
         <p>
 Some workflows will need to reference custom variables in one or more
 of their steps. In this case, the coordinator will need

oas.yaml

@@ -1177,6 +1177,8 @@ components:
           description: An optional step directive that tells the exchange to handle challenge management via a VCALM verifier service it has a zcap for.
         verifiablePresentationRequest:
           $ref: "./components/VerifiablePresentationRequest.yml#/components/schemas/VerifiablePresentationRequest"
+        verifiablePresentation:
+          $ref: "./components/VerifiablePresentation.yml#/components/schemas/VerifiablePresentation"
         callback:
           type: object
           description: A callback that will be called after this step executes.