partly or unimplemented features - now implemented

src/Policy/__Libraries/StellaOps.Policy.Explainability/ServiceCollectionExtensions.cs

@@ -7,6 +7,8 @@ public static class ExplainabilityServiceCollectionExtensions
     public static IServiceCollection AddVerdictExplainability(this IServiceCollection services)
     {
         services.AddSingleton<IVerdictRationaleRenderer, VerdictRationaleRenderer>();
+        services.AddSingleton<IProofGraphBuilder, ProofGraphBuilder>();
+        services.AddSingleton<IProofStudioService, ProofStudioService>();
         return services;
     }
 }