fix: label array items by type instead of "any" in schema reference

[sakinaroufid]

Description

The reference tables show Array[any] in the Type column for some array fields, even though those same fields render with a real type elsewhere on the site.

Why it matters: the Type column is where a reader checks what a field holds. For totals on every extension capability (AP2 Mandate, Buyer Consent, Discount, Fulfillment, Split Payments) it shows Array[any], and for products in catalog lookup it shows Array[any]. Those same fields render correctly as Array[Total] and Array[Product] in the base schemas, and none of the extensions change the field, so a reader gets a worse, blank answer in exactly the places that build on the base.

Cause: the table generator labels an array from items.$ref or a plain items.type. When the item is defined through allOf, or its $ref was inlined while the schema was resolved, neither is present, so it fell back to any. The base tables keep the $ref, which is why they render fine.

Fix: when the simple cases do not apply, recover the item label from the item type, a $ref link, or a title (including titles on allOf branches), and fall back to object rather than any.

Category (Required)

• Core Protocol: Changes to the base communication layer, global context, or breaking refactors. (Requires Technical Council approval)
• Governance/Contributing: Updates to GOVERNANCE.md, CONTRIBUTING.md, or CODEOWNERS. (Requires Governance Council approval)
• Capability: New schemas (Discovery, Cart, etc.) or extensions. (Requires Maintainer approval)
• Documentation: Updates to README, or documentations regarding schema or capabilities. (Requires Maintainer approval)
• Infrastructure: CI/CD, Linters, or build scripts. (Requires DevOps Maintainer approval)
• Maintenance: Version bumps, lockfile updates, or minor bug fixes. (Requires DevOps Maintainer approval)
• SDK: Language-specific SDK updates and releases. (Requires DevOps Maintainer approval)
• Samples / Conformance: Maintaining samples and the conformance suite. (Requires Maintainer approval)
• UCP Schema: Changes to the ucp-schema tool (resolver, linter, validator). (Requires Maintainer approval)
• Community Health (.github): Updates to templates, workflows, or org-level configs. (Requires DevOps Maintainer approval)

Related Issues

None.

Checklist

• I have followed the Contributing Guide (including Conventional Commits title requirements and ! for breaking changes).
• I have updated the documentation (if applicable). Not applicable: this changes how the reference renders, with no separate doc content to edit.
• My changes pass all local linting and formatting checks.
• I have added tests that prove my fix is effective or that my feature works. main.py has no test harness in the repo; verified by rebuilding the spec and diffing every rendered Type cell before and after (1900 cells, 11 changed, 0 regressions). Happy to add a harness if maintainers want one.
• New and existing unit tests pass locally with my changes.
• (For Core/Capability) I have included/updated the relevant JSON schemas. Not applicable.
• I have regenerated Python Pydantic models by running generate_models.sh under python_sdk. Not applicable: no schema change.

Screenshots / Logs (if applicable)

Rendered Type cells before and after, from a full rebuild of the spec.

Before:

Field	Section	Type
totals	Checkout with Split Payments	Array[any]
totals	Checkout with AP2 Mandate	Array[any]
products	Catalog Lookup (lookup_catalog)	Array[any]

After:

Field	Section	Type
totals	Checkout with Split Payments	Array[Total]
totals	Checkout with AP2 Mandate	Array[Total]
products	Catalog Lookup (lookup_catalog)	Array[Product]

A diff of every rendered Type cell across the whole spec confirms exactly 11 cells changed, all Array[any] to Array[Total] or Array[Product], with no other cell affected.

[damaz91]

Thanks @sakinaroufid - LGTM