scan: a folder holding only Steam's own files is not a save

internal/presets/savestats.go

@@ -152,6 +152,12 @@ func measureOne(path string, deadline time.Time) (count int, bytes int64, latest
 		if d.IsDir() {
 			return nil
 		}
+		// Not part of any save (Steam's remotecache.vdf): a folder holding
+		// only that is a game Steam knows of, not a save, and was tracked as
+		// one — twenty-odd games with nothing to sync.
+		if delta.NeverSynced(d.Name()) {
+			return nil
+		}
 		fi, err := d.Info()
 		if err != nil {
 			return nil

internal/presets/savestats_test.go

@@ -211,3 +211,17 @@ func TestMeasure_FolderHoldingOnlyAJunctionIsEmpty(t *testing.T) {
 			saves[0].FileCount)
 	}
 }
+
+// A Steam userdata folder holding only Steam's own remotecache.vdf is not a
+// save: measured, it is empty, and so it is never offered as a new game.
+func TestMeasure_OnlyLauncherFilesIsEmpty(t *testing.T) {
+	dir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(dir, "remotecache.vdf"), []byte("steam"), 0o666); err != nil {
+		t.Fatal(err)
+	}
+	saves := []DiscoveredSave{{SavePath: dir}}
+	Measure(saves)
+	if !saves[0].IsEmpty() {
+		t.Errorf("measured %d file(s): a folder of Steam's bookkeeping counts as a save", saves[0].FileCount)
+	}
+}