- Replaced direct `strings.ToLower` usage with `util.OpenAICompatibleProviderKey` for generating provider keys.
- Updated auth and executor workflows to use namespaced keys for OpenAI-compatible providers.
- Adjusted tests to validate namespaced key handling, including new test cases for provider registration and execution logic.
- Added `OpenAICompatibleProviderKey` helper in `util` for consistent key transformations.
Closes: #3600