hargup/twelve-dollar-server-challenge ? reverse-engineered prompt

Build me a fast implementation of this $12 server challenge API, using SQLite and whatever language or framework makes sense.

I want a small server that passes the provided tests exactly, handles the five endpoints from the spec, and works with the fixed SQLite schema and seed data already in the repo. It should be set up like a real submission, with install, build, and start scripts, plus a short README that explains how to run it and whether it sits behind Nginx or serves directly.

Focus on correctness first, but please optimize it for high load on a tiny 1 vCPU, 2 GB machine. Make sure writes are durable before returning success, and do not rely on any caching that would break the rules. If anything in the spec is unclear, check the repo docs and current language or framework docs online before guessing.