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
fix AF-2460, AF-2463
When recording is started, we start polling the pending raw buffers that are waiting for encoding. The buffers are determined by the cursor of the original raw buffer file. When recording is stopped, we will flush the pending buffers and wrap the encoded chunks into WebM.
```mermaid
sequenceDiagram
participant App as App/UI
participant RecordingFeature as Recording Feature
participant StateMachine as State Machine
participant FileSystem as File System
participant StreamEncoder as Stream Encoder
participant OpusEncoder as Opus Encoder
participant WebM as WebM Muxer
Note over App,WebM: Recording Start Flow
App->>RecordingFeature: startRecording()
RecordingFeature->>StateMachine: dispatch(START_RECORDING)
StateMachine-->>RecordingFeature: status: 'recording'
RecordingFeature->>StreamEncoder: createStreamEncoder(id, {sampleRate, channels})
Note over App,WebM: Streaming Flow
loop Audio Data Streaming
RecordingFeature->>FileSystem: Write raw audio chunks to .raw file
StreamEncoder->>FileSystem: Poll raw audio data
FileSystem-->>StreamEncoder: Raw audio chunks
StreamEncoder->>OpusEncoder: Encode chunks
OpusEncoder-->>StreamEncoder: Encoded Opus frames
end
Note over App,WebM: Recording Stop Flow
App->>RecordingFeature: stopRecording()
RecordingFeature->>StateMachine: dispatch(STOP_RECORDING)
StateMachine-->>RecordingFeature: status: 'stopped'
StreamEncoder->>OpusEncoder: flush()
StreamEncoder->>WebM: muxToWebM(encodedChunks)
WebM-->>RecordingFeature: WebM buffer
RecordingFeature->>FileSystem: Save as .opus file
RecordingFeature->>StateMachine: dispatch(SAVE_RECORDING)
```
Close [BS-2917](https://linear.app/affine-design/issue/BS-2917/【移动端】ios-唤起键盘的edge-case)
This PR fixes an issue where the keyboard cannot be re-triggered on iOS devices after the keyboard toolbar is hidden or executing some actions in keyboard toolbar.
Key changes:
- Preserve and restore the initial input mode when keyboard toolbar shows/hides
- Improve virtual keyboard service interface to better handle keyboard state
- Add proper cleanup of input mode state in component lifecycle
Close [BS-2758](https://linear.app/affine-design/issue/BS-2758).
Support [BS-2583](https://linear.app/affine-design/issue/BS-2583).
### What changed?
- Extend `ChatPanelInput` and `ChatBlockInput` from the same abstract class `AIChatInput` to reduce duplication of code.
- Unify the context interface of `chat-panel` and `chat-block`.
- Rename `items` field to `messages`.
- Remove duplicated type declare.
Support [BS-2583](https://linear.app/affine-design/issue/BS-2583).
### What changed?
- Move chat panel chip components to `/components` folder.
- Separate `chips` and `embeddingProgress` from ChatContextValue.
