Codex/obligation 1.0 models

[niallroche]

Closes accordproject/apap#57

Introduces reviewable 1.0 obligation models based on the working-group proposal. The PR separates durable obligation state, lifecycle transition events and operational fulfilment attempts, and adds settlement and evidence as the first extension profile.

Changes

• Add org.accordproject.obligation@1.0.0 with:
  • an identified, abstract Obligation asset;
  • explicit ObligationTransition events;
  • separate ObligationStatus and FulfilmentAttemptStatus lifecycles;
  • portable PartyRef and hash-bound AgreementRef provenance;
  • exact payments using money@1.0.0.PreciseAmount;
  • payment, performance, notification, remediation, evidence and mitigation obligation types; and
  • revision, authority, basis, evidence and supersession references.
• Add org.accordproject.obligation.settlement@1.0.0 with:
  • explicit payment, refund and penalty-adjustment directions;
  • reproducible derivation and evaluation records;
  • rail-neutral settlement proof; and
  • immutable, hash-linked evidence records for pending, settled, reversed and disputed stages.
• Preserve runtime@0.2.0.Obligation and obligation@0.2.0 unchanged for compatibility.
• Validate both models with Concerto 4.1.5 alongside crypto@1.0.0 and money@1.0.0.

Flags

• Representation decision: confirm that an obligation should be a durable identified asset, with authoritative lifecycle changes represented by ObligationTransition events.
• Lifecycle decision: confirm that legal obligation status remains separate from operational fulfilment-attempt status.
• Core-scope decision: confirm the base obligation and six reusable subtypes as the 1.0 core, while keeping specialised agent and AI-governance taxonomies outside it.
• Profile decision: confirm settlement and evidence as the first extension profile.
• Lifecycle rules: allowed transitions, terminal states, authorised actors, effective-time rules and the meaning of breach must be agreed before publication.
• Settlement rules: canonical unit scales, non-ISO asset identifiers, amount constraints and hashing test vectors must be normative before publication.
• Migration: a normative mapping from the legacy event-only obligation model is still required.
• Repository ownership: reusable vocabulary belongs in accordproject/models; APAP TriggerResponse changes should be handled separately in the APAP repository.
• This PR does not create byte-identical contract@1.0.0 or runtime@1.0.0 models solely for numerical alignment.
• This PR does not duplicate the signature work in feat(signature): add org.accordproject.signature@1.0.0 #195. Evidence-to-signature binding can follow once its verification semantics are settled.
• The two commits currently require DCO sign-off before merge.

Screenshots or Video

Not applicable. This PR contains Concerto model changes only.

Related Issues

• Issue accordproject/apap#57
• Pull Request accordproject/apap#89
• Pull Request accordproject/models#195
• Pull Request accordproject/apap#183

Author Checklist

• Ensure you provide a DCO sign-off for your commits using the --signoff option of git commit.
• Vital features and changes captured in unit and/or integration tests
• Commits messages follow AP format
• Extend the documentation, if necessary
• Merging to main from niallroche:codex/obligation-1.0-models