CHISINAU, Moldova — Moldovans are casting votes in a decisive presidential runoff Sunday that pits pro-Western incumbent Maia Sandu against a Russia-friendly opponent, as ongoing claims of voter fraud and intimidation threaten democracy in the European Union candidate country. In the first round held October 20, Sandu obtained 42% of the ballot but failed to win an outright majority. She will face Alexandr Stoianoglo, a former …