<!-- 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- Cleaned up internal APIs by deleting unused exports, imports, and outdated code, enhancing maintainability.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 -->
Closes: [BS-3358](https://linear.app/affine-design/issue/BS-3358/remark-callout-plugin)
Closes: [BS-3247](https://linear.app/affine-design/issue/BS-3247/callout-markdown-adapter-适配)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Added support for callout blocks in Markdown, enabling recognition and conversion of callout syntax (e.g., `[!emoji]`) to and from block structures.
- **Bug Fixes**
- Improved handling to distinguish callout blocks from regular blockquotes and paragraphs during Markdown processing.
- **Tests**
- Introduced comprehensive tests for callout block serialization, deserialization, and plugin behavior to ensure correct Markdown handling.
- **Chores**
- Added a new dependency for Markdown AST traversal.
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Saul-Mirone