- Introduced `xai-api-key` to configuration for supporting xAI provider integration.
- Added API key operations: creation, updates, deletion, and sanitization.
- Implemented backend enhancements for credential-specific routing, response filtering with model aliasing, and WebSocket handling for xAI services.
- Included extensive test coverage to validate configuration parsing, CRUD operations, and the new functionalities.
- Updated related modules to handle `xai-api-key`, including the watcher, management handlers, and configuration sanitizers.