DCQL: credential sets (identity alternatives)

Scenario

A verifier needs proof of identity and accepts any one of PID, Passport, or Photo ID. The wallet presents whichever the holder has; options are tried in order.

Prerequisites

• An iGrant.io Organisation Wallet Suite (OWS) API key. Get it from support@igrant.io. Keep it on the server, in an environment variable or a secret manager. The browser never sees it.
• The OWS environment the key belongs to. The default is demo (https://demo-api.igrant.io). Use staging (https://staging-api.igrant.io) only when the integrator asks for it. A key works only in its own environment.