Summary

As part of this change, the old/legacy API key authentication method will be deprecated and no longer valid.

We should be updating the two opportunity retrieval endpoints to support both JWT auth (login.gov) and the new API key auth system:

GET /v1/opportunities/:opportunity_id
GET /v1/opportunities/:legacy_opportunity_id
This aligns these endpoints with our broader API authentication strategy while ensuring external API consumers can continue accessing opportunity data through the new API key system.

Acceptance criteria

• Changes are not merged to main, put it in a draft PR
• 2 endpoints are updated to support both types of auth
• Comprehensive unit tests are updated and changes are tested locally