## Why
Publishing the MCP server to the ChatGPT app directory requires proving
we own the host that serves it. The submission portal issues a token and
fetches `https://whisper.money/.well-known/openai-apps-challenge`,
expecting the bare token back. That path currently 404s.
## What
- `GET /.well-known/openai-apps-challenge` returns
`OPENAI_APPS_CHALLENGE` as `text/plain`, nothing else — no JSON
envelope, no extra tokens.
- Aborts with 404 when the token is unset, so a host without the
variable configured cannot answer with an empty body that the verifier
would read as a mismatched token.
- Token lives in config/env rather than the repo: it is per-plugin and
rotates independently of the code.
## Testing
`tests/Feature/OpenAiAppsChallengeTest.php` covers both branches: the
token is served verbatim when configured, and the route 404s when it is
not.
The production env var is already set, so the endpoint answers once this
deploys.
Víctor Falcón