It has quietly joined the earbuds, the portable charger and the foldable umbrella as a daily non-negotiable. The handheld fan – once limited to being a travel essential or seasonal afterthought – is increasingly becoming a fixture of Singapore life, visible on the MRT, at hawker centres and concert venues, in the hands of parents, teenagers, office workers and travellers alike.Part of that shift can be traced to brands such as JisuLife, a consumer electronics company founded in 2016, which began treating the handheld fan not simply as relief from the heat, but as a design object worth carrying. Softened edges and…