Staring at a bug report that makes no sense. Data gone. No error. No warning. No stack trace. Just… gone. Your app writing files using the File System Access API — which, by the way, is genuinely one of the most exciting things that's happened to the browser in years. A user picks a folder. You write to it. Clean, native, no server involved. The dream, right? Except on mobile, the dream has a bad habit of dying quietly. Here's what was actually happening The browser process got killed in the background. Completely normal — Android does this all the time when memory gets tight. Writable stream was mid-write when it happened. No error was thrown. The write just… didn't complete. And then you start digging. And you realize — this isn't a bug you can patch. It was a category of problem.…