Context missing top-level term definitions for UNTP classes used as type values

The 0.7.0 UNTP context defines top-level term entries for the credential-root classes (ConformityScheme, Party, Facility, Product, etc.) but not for the helper/leaf classes that appear as nested object types: Link, Endorsement, Image, Score, ScoringFramework, Classification, Performance, Measure, StandardAlignment, RegulatoryAlignment, and others. Any document that sets "type": ["Link"] (or similar) on a nested object (e.g. a conformity scheme) fails expansion with a "relative @type reference" warning because the class name cannot be resolved to an absolute IRI.

Steps to reproduce

With the type alias issue resolved (see issue #650 (closed)) or VCDM v2 prepended, expand a document containing a nested typed object:

"conformsTo": {
  "type": ["Link"],
  "linkURL": "...",
  "linkName": "..."
}

Observed

jsonld.ValidationError: Safe mode validation error.
code: "relative @type reference"
message: "Relative @type reference found."
details: { type: "Link" }

Expected

Classes (e.g. Link) resolve to the corresponding IRI (e.g. https://vocabulary.uncefact.org/untp/Link), and expansion succeeds.