Refactor repo for standalone portable provider workflow

internal/provider/provider_acc_test.go

@@ -6,10 +6,13 @@ import (
 )
 
 func TestAccScaffold(t *testing.T) {
-	if os.Getenv("TF_ACC") == "" || os.Getenv("DYNU_API_KEY") == "" {
+	if os.Getenv("TF_ACC") != "1" || os.Getenv("DYNU_API_KEY") == "" {
 		t.Skip("set TF_ACC=1 and DYNU_API_KEY to enable acceptance tests")
 	}
 
+	// Optional: DYNU_DOMAIN may be used by future acceptance test cases.
+	_ = os.Getenv("DYNU_DOMAIN")
+
 	// Acceptance tests for read-only data sources are intentionally scaffolded in phase 1.
 	// Add terraform-plugin-testing based test cases in a follow-up with stable fixtures.
 }