Make ontology queries visually distinct and less overlapping

[paolino]

Problem

The ontology queries currently do real OWL/RDFS extraction work, but several of them render graphs that look too similar to each other. In practice this makes it hard to understand the value of the ontology feature, because Ontology Classes, Class Hierarchy, and related views often feel like the same graph with a different title.

This is partly a query-shape problem and partly a presentation problem. Even when the result sets differ, the UI does not make class nodes, subclass edges, properties, and instance/data nodes visually distinct enough.

Acceptance criteria

• Review the ontology query set and reduce unnecessary overlap between ontology-focused views.
• Make it visually obvious when the user is looking at class hierarchy, ontology properties, or mixed schema/data results.
• Expose enough RDF/OWL semantics in the UI that different ontology queries are meaningfully distinguishable.
• Verify on graph-browser self-ontology and a downstream ontology dataset that the ontology queries no longer all feel like the same graph.

Context

• Related feature issue: Auto-generate ontology view from OWL/RDFS triples #50
• Related PR: feat: auto-generate ontology view from OWL/RDFS triples #52
• Current feedback from manual inspection is that the ontology queries often do not demonstrate clear value because they appear too visually overlapping.
• This is separate from publishing dereferenceable namespace documents tracked in Publish dereferenceable ontology namespace documents #53.