- Updated `buildCodexConfigModels` to default to `CodexProModels` when no models are explicitly configured, ensuring consistent behavior. - Refined logic in `resolveConfigCodexKey` to streamline model selection and exclusion handling. - Added comprehensive tests for default, explicit, and exclusion-based model configurations. - Introduced `TestRegisterConfigAPIKeyAuthsCodexModelModes` to validate runtime model registration scenarios. - Enhanced test utility functions for improved readability and reuse.