### TL;DR
Refactored extension registration to follow a more modular approach by moving extensions to their respective block packages.
### What changed?
- Removed centralized registration of several extensions from `store.ts` in the main package
- Moved the following extensions to their respective block packages:
- `CodeMarkdownPreprocessorExtension` to the code block package
- `LatexMarkdownPreprocessorExtension` to the latex block package
- `EmbedIframeConfigExtensions` and `EmbedIframeService` to the embed block package
- `ImageStoreSpec` removed from central registration
- Cleaned up unused arrays and imports in the main store file
- Removed empty `defaultBlockPlainTextAdapterMatchers` array
### How to test?
1. Verify that markdown preprocessing for code and latex blocks still works correctly
2. Check that iframe embeds function properly
3. Ensure image handling continues to work as expected
4. Test import/export functionality for all affected block types
### Why make this change?
This change improves code organization by following a more modular architecture where each block package is responsible for registering its own extensions. This approach reduces coupling between packages, makes the codebase more maintainable, and follows the principle that extensions should be registered where they are defined.
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
AudioMedia entity for loading & controlling a single audio media
AudioMediaManagerService: Global audio state synchronization across tabs
AudioAttachmentService + AudioAttachmentBlock for manipulating AttachmentBlock in affine - e.g., filling transcription (using mock endpoint for now)
Added AudioBlock + AudioPlayer for rendering audio block in affine (new transcription block whose renderer is provided in affine)
fix AF-2292
fix AF-2337
Saul-Mirone