Adopt ConfigKit for pipeline loading

internal/config/artifact_families_test.go

@@ -8,6 +8,15 @@ import (
 	"testing"
 )
 
+func absolutePath(t *testing.T, path string) string {
+	t.Helper()
+	absolute, err := filepath.Abs(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return absolute
+}
+
 func TestArtifactFamiliesExpandCanonicalCharactersDeterministically(t *testing.T) {
 	dir := t.TempDir()
 	writePartyResolutionFile(t, dir+"/party.yml", `schema_version: narratio.party.v1
@@ -148,7 +157,7 @@ func TestArtifactFamilyStrictDecodeRejectsUnknownFields(t *testing.T) {
 	dir := t.TempDir()
 	pipelinePath, _, _ := writeArtifactFamilyConfig(t, dir, artifactFamilyPipelineYAML(validFamilyYAML+"    unsupported: true\n"))
 	_, err := LoadPipeline(pipelinePath)
-	if err == nil || !strings.Contains(err.Error(), "field unsupported not found") {
+	if err == nil || !strings.Contains(err.Error(), "decode.unknown_field") {
 		t.Fatalf("LoadPipeline() error = %v", err)
 	}
 }