A year since the dust settled on the Singapore general election, leadership resignations in two small opposition parties signal a period of post-poll recalibration after disappointing results.The once-promising Progress Singapore Party (PSP), led by ruling People’s Action Party (PAP) defector Tan Cheng Bock, was dealt an “existential blow” on Monday, analysts say, following the resignations of two central executive committee members.Stephanie Tan, 38, was a newcomer who ran in the election,...