[UDNA] PR #13 ready for review -- processing model, conformance classes, test vectors, and JSON-LD context

Hello all,

PR #13 is now open for review and represents a significant update to the UDNA
Community Group Draft specification.

GitHub PR: https://github.com/w3c-cg/udna/pull/13


Summary of changes:

Normative additions

- Conformance classes: UDNA Resolver, UDNA Client, and UDNA Gateway are now
  explicitly defined with their respective requirements.

- Processing model: The resolution algorithm is now specified as a formal
  nine-step processing model. Each step includes the specific error code
  returned on failure. This is separated from the data model to allow
  independent evolution.

- ResolutionResult validity rules: Five normative rules (VR-1 through VR-5)
  define when a resolution result is considered valid, covering URL syntax,
  DID Document conformance, service entry correspondence, metadata
  completeness, and verification method membership.

- Gateway constraint: A single normative rule (GW-1) requires gateways to
  preserve target URL semantics without modification.

- Test vectors: Five deterministic test vectors (TV-1 through TV-5) are
  provided for inter-implementation validation. Each specifies the full
  context DID Document, the input UDNA address, and the expected output or
  error code.

- JSON-LD context: The context referenced by the ResolutionResult data model
  is now published in full at Appendix C and at its canonical URL.

Informative additions

- Browser integration model: A four-step progression from protocol
  registration through native resolution, gateway fallback, and extension
  hooks.

- Resolution hints exploration: Four invariants to preserve DID method
  neutrality if optional hints are adopted in a future version.

Modifications

- Introduction and abstract now position UDNA in the addressing stack
  alongside DNS and DIDs.

- Relationship with Solid/WebID adjusted to use permissive language.

- DIDComm dependency clarified as optional.

- Threat model updated to include gateway interception.

Review timeline

The PR is open for review. If there are no substantive objections or
blocking feedback, the intention is to merge in approximately two weeks.

Comments on the PR or replies to this thread are welcome.

Best regards,

Amir Hameed Mir