Close [BS-3029](https://linear.app/affine-design/issue/BS-3029/frame-里面的-shape-没办法进入文本编辑模式)
Close [BS-3082](https://linear.app/affine-design/issue/BS-3082/按s切换至shape工具，在白板上点击会创建两个shape)
Close [BS-3091](https://linear.app/affine-design/issue/BS-3082/按s切换至shape工具，在白板上点击会创建两个shape)
## Fix Shape Tool Issues
This PR addresses several issues with the shape and mindmap tools functionality in the editor:
1. **Fix text editing after mode switching**: Resolves an issue where users couldn't edit text in shapes after switching editor modes. The fix ensures the edgeless block is properly retrieved when double-clicking on a shape.
2. **Improve tool switching behavior**: Fixes issues with tool overlays not showing or being repeated when switching between tools. This includes:
- Properly handling tool overlay visibility
- Ensuring only one tool is active at a time when using keyboard shortcuts
- Adding proper cleanup when switching tools
3. **Add comprehensive tests**: Adds new test cases to verify:
- Shape creation with keyboard shortcuts
- Shape text editing after mode switching
- Tool switching behavior with keyboard shortcuts
### TL;DR
Refactored the BlockSuite turbo renderer to use a hierarchical tree structure for layouts instead of a flat list, improving rendering accuracy and performance.
### What changed?
- Redesigned the layout system to use a tree structure (`ViewportLayoutTree`) that better represents the document hierarchy
- Added `blockId` to all layout objects for better tracking and debugging
- Updated the layout query mechanism to work with models directly instead of components
- Enhanced error handling with more descriptive warnings and error messages
- Improved the painting process to traverse the layout tree recursively
- Fixed viewport coordinate calculations for more accurate rendering
- Updated the worker communication to support the new tree-based layout structure
### Why make this change?
The previous flat layout structure didn't properly represent the hierarchical nature of documents, leading to rendering issues with nested blocks. This tree-based approach:
1. Better represents the actual document structure
2. Improves rendering accuracy for nested elements
3. Makes debugging easier with more consistent block identification
4. Provides a more robust foundation for future rendering optimizations
5. Reduces the likelihood of rendering artifacts when scrolling or zooming
Close [BS-3079](https://linear.app/affine-design/issue/BS-3079).
- Separate the create session logic from the `createMessage function`.
- Ensure the session is created before executing any chat or actions.
- Convert the `AIActions` into asynchronous functions.
- Transfer the update prompt name logic to the chat action.
- Introduce a networkSearch field in `AITextActionOptions`.
- Eliminate the redundant `LAST_ROOT_SESSION_ID`.
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
