Remove superseded configuration loaders and consolidate runtime tests

output_contract_contract_test.go

@@ -6,22 +6,10 @@ import (
 	"testing"
 
 	"gitea.maximumdirect.net/eric/promptkit"
-	"gitea.maximumdirect.net/eric/promptkit/testfixture"
 )
 
 func TestPreparationRejectsInvalidOutputContractWithPublicError(t *testing.T) {
-	engine, err := testfixture.NewEngine(
-		testfixture.Config{},
-		testfixture.WithPromptFS(contractPromptFS("prompt", "profile", "message"), "."),
-		testfixture.WithProfiles(testfixture.Profile{
-			ID:       "profile",
-			Endpoint: "http://example.test/v1",
-			Model:    "model",
-		}),
-	)
-	if err != nil {
-		t.Fatalf("construct engine: %v", err)
-	}
+	engine := newSimpleEngine(t, "message")
 
 	for _, tc := range []struct {
 		name     string