Tackling Synology's Opaque "Invalid File Format" Error

A few months back I bought a new Synology NAS and decided to, on a whim, build an app for it from scratch. Partly to see how well Claude Code could handle it, mostly to see whether the option was open to me.&#xA;Starting off with the most basic app, the Python backend worked, the tests passed, the SPK archive assembled cleanly, but then Synology&rsquo;s Package Center rejected it with the error…