Alex Eala became the name the Philippines learned to watch. Her older brother Miko knows what it took to get there because he was there first. There is a particular kind of intimacy that comes from losing to the same person over and over again — and for Alex Eala, that person was her older brother. Before the packed arenas, the national flags, the 4 a.m. wake-ups and the increasingly routine business of beating players whose names once belonged to the television, there was Miko on the other side of the net. Older, better, already further along in the sport. Alex has said she used to practice constantly with him, and even after he had stopped playing for months, she still couldn’t beat him. It’s a funny detail in the origin story of one of the Philippines’ biggest sporting figures, and a more revealing one than the usual family-tree version of the Eala story: Miko didn’t merely grow up alongside Alex’s tennis career. He was part of the environment that made it possible. The siblings …