Carry optional prompt labels through results

internal/configuration/listing.go

@@ -22,6 +22,9 @@ func (state *loaded) ListPrompts(ctx context.Context) ([]domain.PromptIdentity,
 		return nil, err
 	}
 	prompts := append([]domain.PromptIdentity(nil), state.promptIDs...)
+	for index := range prompts {
+		prompts[index].Version = stringPointerValue(prompts[index].Version)
+	}
 	if err := ctx.Err(); err != nil {
 		return nil, err
 	}