Verify ReleaseKit against a disposable remote

docs/roadmap/implementation.md

@@ -161,7 +161,7 @@ the default suite and `./scripts/check.sh` pass with the selected Go and
 prepared dependencies; the retained tests protect development checks and
 profile wiring without duplicating ReleaseKit's generic behavior.
 
-## Stage 6: Exercise the migration without publishing ConfigKit
+## Stage 6: Exercise the migration without publishing ConfigKit — Complete
 
 1. Build ReleaseKit from the candidate's `go.mod` selection with the latest
    selected local Go patch for that minimum's series. Use that same executable

releasekit_profile_test.go

@@ -39,8 +39,12 @@ func TestReleaseKitProfile(t *testing.T) {
 	if profile.Remote != "origin" {
 		t.Errorf("remote = %q, want origin", profile.Remote)
 	}
-	if profile.ExpectedPushURL != "https://gitea.maximumdirect.net/eric/ConfigKit.git" {
-		t.Errorf("expected push URL = %q", profile.ExpectedPushURL)
+	wantPushURL := "https://gitea.maximumdirect.net/eric/ConfigKit.git"
+	if fixturePushURL := os.Getenv("CONFIGKIT_TEST_EXPECTED_PUSH_URL"); fixturePushURL != "" {
+		wantPushURL = fixturePushURL
+	}
+	if profile.ExpectedPushURL != wantPushURL {
+		t.Errorf("expected push URL = %q, want %q", profile.ExpectedPushURL, wantPushURL)
 	}
 	goValidation := profile.Validation.Go
 	if !goValidation.Race || !goValidation.FullVet {