Build a tiny HTTP API server in the sandbox called app.py. It must use only the
Python standard library (e.g. http.server) so it runs anywhere.

Endpoints:

1. `GET /health`  -> 200 with JSON body {"status": "ok"}
2. `GET /items/<id>` -> 200 with JSON body {"id": <id>, "name": "item-<id>"}
   for integer ids 1..100; 404 with JSON {"error": "not found"} otherwise.

Server must listen on 0.0.0.0:8765. Content-Type must be application/json on
every response. Respond to unknown paths with 404 JSON.

The verifier starts your server as a subprocess, waits for /health, then checks
/items/<id> for both a valid id and an out-of-range id, and finally kills the
server.

Test it against the verification oracle before replying DONE.
When the goal is met and verified, reply exactly: DONE.
