<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Refactor**
- Simplified search menu logic by removing unnecessary filtering and parameters from menu item generation. No changes to visible functionality.
- **Bug Fixes**
- Improved search index matching to retrieve all relevant entries, enhancing search accuracy.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Closes: [BS-3137](https://linear.app/affine-design/issue/BS-3137/在-bs-添加-blobstate-接口)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Introduced real-time status tracking for file upload and download operations, allowing users to monitor progress and errors more effectively.
- **Improvements**
- Enhanced icon display for attachments, providing a refreshed visual experience.
- Improved update frequency and accuracy for file synchronization status indicators.
- **Bug Fixes**
- Refined internal logic for filtering status updates, ensuring more precise feedback during file operations.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
To close [BS-2870](https://linear.app/affine-design/issue/BS-2870/支持识别-和-[-包裹内容为公式)
## Add Markdown Preprocessor Extension and Enhanced LaTeX Support
### Markdown Preprocessor Extension
This PR introduces a new preprocessor extension for Markdown adapters that allows preprocessing of content before conversion:
Adds a new PreprocessorManager for handling text transformations
Introduces extensible preprocessor interface that supports different processing levels (block/slice/doc)
Integrates preprocessor extension into the existing Markdown adapter workflow
### LaTeX Support Enhancement
Extends LaTeX support to handle both traditional and alternative syntax:
Adds support for backslash LaTeX syntax:
Block math: ```\[...\] ``` alongside existing ```$$...$$```
Inline math: ```\(...\) ``` alongside existing ```$...$```
Implements LaTeX preprocessor to standardize syntax before conversion
Updates tests to cover both syntax variants
liuyi
