Replace validator contracts with raw output validation

internal/framework/pipeline/validator_registry_test.go

@@ -1,6 +1,7 @@
 package pipeline
 
 import (
+	"context"
 	"testing"
 
 	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
@@ -56,3 +57,33 @@ func TestValidatorRegistryBehavior(t *testing.T) {
 		},
 	})
 }
+
+func TestValidatorRegistryRejectsUnsupportedExecutionClass(t *testing.T) {
+	registry := NewValidatorRegistry()
+	if err := registry.Register("invalid-validator", func() (contracts.Validator, error) {
+		return invalidExecutionClassValidator{name: "invalid-validator"}, nil
+	}); err != nil {
+		t.Fatalf("Register() error = %v, want nil", err)
+	}
+
+	_, err := registry.Build("invalid-validator")
+	if err == nil {
+		t.Fatal("Build() error = nil, want unsupported execution class error")
+	}
+}
+
+type invalidExecutionClassValidator struct {
+	name string
+}
+
+func (validator invalidExecutionClassValidator) Name() string {
+	return validator.name
+}
+
+func (validator invalidExecutionClassValidator) ExecutionClass() contracts.ExecutionClass {
+	return contracts.ExecutionClass("unsupported")
+}
+
+func (validator invalidExecutionClassValidator) Validate(ctx context.Context, req contracts.ValidationRequest) (contracts.ValidationResult, error) {
+	return contracts.ValidationResult{Approved: true}, nil
+}