impr(ligatures): always enable in Zen and Custom modes for always correct script rendering (@byseif21) (monkeytypegame#6694)

### Description

fixes broken ligature rendering in zen mode by always enabling
ligatures, ensuring that scripts like Arabic etc .. display correctly
and words connect as expected in any scenario or direction!.

Author: byseif21

frontend/src/ts/test/test-ui.ts

@@ -1186,7 +1186,7 @@ export function setRightToLeft(isEnabled: boolean): void {
 }
 
 export function setLigatures(isEnabled: boolean): void {
-  if (isEnabled) {
+  if (isEnabled || Config.mode === "custom" || Config.mode === "zen") {
     $("#words").addClass("withLigatures");
     $("#resultWordsHistory .words").addClass("withLigatures");
     $("#resultReplay .words").addClass("withLigatures");