Fix for issue #93 jsonld context

[jgeluk]

Summary

• Fix: dist/dprod.jsonld is now a proper JSON-LD context document (single top-level @context), not an ontology dump. Resolves issue #93.
• Ontology: The ontology JSON-LD is emitted separately as dist/dprod-ontology.jsonld (contains @graph).
• Backward compatibility: Other generated artifacts (dprod-all.jsonld, *.ttl, *.rdf, shapes) remain unchanged.

What changed

• Generator (spec-generator/main.py):
  • Generates a compact JSON-LD context mapping all DPROD terms and prefixes.
  • Writes the context to dist/dprod.jsonld.
  • Writes the ontology dump to dist/dprod-ontology.jsonld.
• Tests (tests/test_context.py):
  • Assert dist/dprod.jsonld is a pure context (only @context at the top level).
  • Assert dist/dprod-ontology.jsonld contains @graph.
  • Validate that a minimal JSON-LD instance using the context expands to expected triples (DataProduct type and dataProductOwner).
  • Use PyLD to convert JSON-LD → N-Quads → rdflib Dataset (clean, warning-free parsing).
• Dependencies (requirements.txt):
  • rdflib>=7.1.4,<9
  • pyld>=2,<3

Rationale

• Previously, dist/dprod.jsonld was an ontology dump, which is not usable as a JSON-LD context and caused failures when consumed as such.
• Splitting context and ontology aligns with best practices and avoids term resolution issues.

How to consume

• Reference the context once at the top level of JSON-LD instance documents:
  • "@context": "https://ekgf.github.io/dprod/dprod.jsonld"
• Avoid redefining or nesting @context in the same document.

Verification

• Local build: Python 3.13, .venv.
• Test run: 3 tests passed, 0 warnings.