fix: correct OpenAI domain verification token

[adityaoberai]

Summary

Corrects the token served at /.well-known/openai-apps-challenge. The value shipped in #119 had two mistyped characters, so OpenAI domain verification would fail against the deployed endpoint. The unit test's expected body is updated to match.

Testing

• black --check src tests
• ruff check src tests
• python -m unittest tests.unit.test_http_app (33 tests pass)

🤖 Generated with Claude Code

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge; the corrected token is consistently served and validated through the public HTTP route.

Summary

• Changes the challenge response from Ea1/BJn to Eal/BJr.
• Preserves the endpoint's successful plain-text response contract.

_{Reviews (1) · Last reviewed commit: "fix: correct OpenAI domain verification ..."}