Prove structured Relay claims survive the eSignet UserInfo exchange

[jeremi]

Context

We want the social registry eSignet flow to authenticate a person and release household context as relationship data. A clean OIDC shape may use a top-level structured claim such as household_memberships, whose value is an array of objects.

Current code appears structurally capable of this: the Relay client parses object/array JSON values into Java Map/List, ClaimMapper copies values as Object, and UserInfoSigner serializes the final UserInfo map as JSON. However, current tests and docs mostly prove scalar, number, and boolean claims, not nested objects/arrays.

Desired behavior

• Support a top-level claim such as household_memberships whose value is an array of objects.
• Keep eSignet accepted claims top-level only. Nested selection like household_memberships[].relationship is out of scope unless eSignet/Relay later define it explicitly.
• Document the configuration pattern:
  • MOSIP_ESIGNET_OPENID_SCOPE_CLAIMS includes household_memberships
  • registry.esignet.claim-map.household_memberships=household_memberships
  • Relay profile declares/releases household_memberships

Acceptance criteria

• Add a Relay client test proving object and array values are parsed and preserved.
• Add a ClaimMapper test proving a structured released value is copied into UserInfo unchanged.
• Add an exchange test that decodes the signed UserInfo JWS and asserts household_memberships remains an array of objects.
• Update docs to state: structured values are supported as top-level claims; fine-grained nested consent/selection is not currently supported.

Notes

This is important for the social registry model: login subject is a person, while household membership is contextual relationship data.