feat(spec)!: enforce strict allOf form for derivation and redesign tr…

[aviator5]

…aits as URN-referenced types

• Add §3.2.1 (Top-level composition rules): derived GTS Type Schemas MUST use the canonical single-item allOf with a $ref to the immediate parent; overlay constraints live at the top level. Top-level anyOf/oneOf/not are forbidden on all GTS Type Schemas (nested usage is unaffected). Rationale captured in ADR-0002.
• Rewrite §9.7 traits model: x-gts-traits-schema becomes a single GTS Type URN string referencing a registered trait-type; inline schema, $ref, and composition forms are removed. Trait-types are first-class GTS Type Schemas with their own parallel-derivation chain. Shallow merge with immutable-once-set semantics preserved.
• Make the trait-completeness rule explicit: a non-abstract host with unresolved required trait fields is invalid by definition; registry MUST reject it at registration and OP#6 MUST reject instances of it as defense in depth.
• Extend OP#12 to enforce the structural rules from §3.2.1 in addition to the existing constraint-compatibility checks.
• Migrate all examples in events/types/, mcp/types/, and typespec/vms/types/ to strict Form A and the new trait-type model. Add gts.x.core.traits.event_meta.v1~ as the canonical trait-type referenced by the base event schema.
• Update the register_derived test helper to emit strict Form A (single-item allOf + overlay spread at top level). Add register_trait_type and register_host_with_trait_ref helpers.
• Add 15 structural test classes to test_op12_* covering canonical form, rejections (Form B, 3+ items, no-$ref, multi-$ref, skip-level, wrong parent, hybrid, top-level union/negation, base-with-allOf), and accepted nested-union shapes.
• Rewrite test_op13_* (38 classes) around URN-referenced trait-types: value validation cases, trait-type derivation (narrowing, loosening rejection, field extension, default inheritance), parallel-derivation rules, abstract vs concrete completeness, MAJOR-version pinning, cycle detection, and instance-validation defense-in-depth.
• Migrate the three trait-aware tests in test_refimpl_x_gts_final_abstract.py to the URN model.
• Add ADR-0002 (MADR) with worked Option-1..4 comparison, running example, and explicit payload behavior under each option.
• Log change as version 0.12 (BREAKING).

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 39a1ff7a-bd05-452e-8352-8e178f165546

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[aviator5]

superseded with #77