Implements #322: ConstructTemplate/ParameterDescriptor/ConstructTemplateRegistry
with injection-safe {{param}} rendering, Blazegraph CONSTRUCT-aware execute_sparql
extension, execute_construct_template (render->execute->parse->persist), and a
construct_template pipeline step. RDF4J/Jena support deferred to a follow-up issue.
Closes#322
- Added _resolve_datatype_iri() to expand known prefixes (xsd/rdf/rdfs/owl/skos)
to full IRIs instead of blindly wrapping in <...>, fixing invalid SPARQL like
<xsd:integer>
- Validated language tags against RFC 5646 regex to prevent SPARQL injection
via metadata["lang"] values containing whitespace or punctuation
- Validated datatype IRIs for whitespace/special characters before interpolation
- Extended test suite from 7 to 15 cases covering prefix expansion, injection
rejection, and all accepted input forms
Sameer6305