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## Summary by CodeRabbit
- **Bug Fixes**
- Improved code block preview rendering to only display the preview when
appropriate, preventing unwanted previews.
- **Refactor**
- Simplified the HTML preview system by always using a secure
iframe-based approach and removing the WebContainer integration.
- Updated iframe permissions and content delivery for enhanced security
and compatibility.
- **Chores**
- Removed the "Enable Web Container" feature flag and all related
internal logic.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Close [AI-160](https://linear.app/affine-design/issue/AI-160)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Improved preview state management for code blocks, ensuring consistent behavior in both editable and readonly modes.
- **Refactor**
- Streamlined the way preview state is toggled and displayed for code blocks, resulting in a more reliable and maintainable user experience.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Added a toggle in the code block toolbar to show or hide line numbers for individual code blocks.
- The display of line numbers now respects both global and per-block settings, allowing more flexible control.
- **Style**
- Updated styles to hide line numbers when disabled via the new toggle option.
- **Tests**
- Added end-to-end tests to verify toggling line numbers visibility and undo/redo behavior.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Refactor**
- Improved history and undo/redo management across the app by introducing a dedicated history extension. Undo/redo operations now use a more focused undo manager, resulting in clearer and more consistent behavior.
- **Documentation**
- Updated API documentation to reflect changes in history management, including revised method signatures and removal of outdated event references.
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<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Refactor**
- Unified internal data access by replacing all references from `doc` to `store` across all components, blocks, widgets, and utilities. This affects how readonly state, block operations, and service retrieval are handled throughout the application.
- **Tests**
- Updated all test utilities and test cases to use `store` instead of `doc` for document-related operations.
- **Chores**
- Updated context providers and property names to reflect the change from `doc` to `store` for improved consistency and maintainability.
No user-facing features or behaviors have changed.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Introduced a preview mode for code blocks, allowing users to toggle between code and rendered previews (e.g., HTML output) directly within the editor.
- Added a preview toggle button to the code block toolbar for supported languages.
- Enabled dynamic rendering of code block previews using a shared WebContainer, allowing live HTML previews in an embedded iframe.
- Added HTML preview support with loading and error states for enhanced user feedback.
- Integrated the preview feature as a view extension provider for seamless framework support.
- **Bug Fixes**
- Improved toolbar layout and button alignment for a cleaner user interface.
- **Tests**
- Added end-to-end tests to verify the new code block preview functionality and language switching behavior.
- **Chores**
- Updated development server configuration to include enhanced security headers.
- Added a new runtime dependency for WebContainer support.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
EYHN