<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Refactor**
- Streamlined and consolidated block and inline extension exports by removing multiple block-spec and inline extension arrays from public APIs.
- Reduced exported constants, types, and utility functions related to various block and embed features.
- Simplified the codebase by removing deprecated type guards, adapter extensions, and redundant extension groupings.
- **Chores**
- Cleaned up internal APIs by deleting unused exports, imports, and outdated code, enhancing maintainability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
