[BUG] KGVisualizer.visualize_network() does not accept a KnowledgeGraph object

Description: KGVisualizer.visualize_network() is typed as graph: Dict[str, Any] and internally accesses graph["entities"] and graph["relationships"] directly. Passing a KnowledgeGraph instance — the natural output of GraphBuilder.build() — silently does nothing: no error, no progress, no output. Expected behavior: visualize_network(kg) where kg is a KnowledgeGraph should work, since the entire purpose of the visualizer is to visualize the result of building a knowledge graph. Actual behavior: The method silently returns without rendering. No exception is raised, no warning is logged. Workaround: fig = viz.visualize_network( {"entities": entities, "relationships": relationships}, output="interactive", ) Steps to reproduce: from semantica.kg.graph_builder import GraphBuilder from semantica.visualization import KGVisualizer kg = GraphBuilder().build([{"entities": [...], "relationships": [...]}]) viz = KGVisualizer(layout="force") fig = viz.visualize_network(kg, output="interactive") # silent no-op Version: semantica 0.4.0