<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Footnote definitions and "Sources" headings are now always included in notes, without requiring a feature flag.
- Enhanced footnote-related content with additional citation-style blocks such as bookmarks, embedded documents, and attachments.
- **Chores**
- Removed the citation feature flag and its related configuration, logic, and translations from the application.
- **Documentation**
- Updated localization files to remove entries related to the citation experimental feature.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Closes: [BS-3369](https://linear.app/affine-design/issue/BS-3369/昨天发现-footnote-中的引用，和实际渲染出来的对不上)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Bug Fixes**
- Improved handling of URLs in footnote definitions to ensure all URLs are fully percent-encoded, including those that were only partially encoded before.
- **Tests**
- Added a new test case to verify that partially encoded URLs in footnotes are now fully encoded as expected.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Closes: [BS-3122](https://linear.app/affine-design/issue/BS-3122/footnote-definition-adapter-适配)
Closes: [BS-3123](https://linear.app/affine-design/issue/BS-3123/几个-block-card-view-适配-footnote-态)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Introduced a new citation card component and web element for displaying citations.
- Added support for citation-style rendering in attachment, bookmark, and linked document blocks.
- Enabled citation parsing from footnote definitions in markdown for attachments, bookmarks, and linked docs.
- Added a feature flag to enable or disable citation features.
- Provided new toolbar logic to disable downloads for citation-style attachments.
- **Improvements**
- Updated block models and properties to support citation identifiers.
- Added localization and settings for the citation experimental feature.
- Enhanced markdown adapters to recognize and process citation footnotes.
- Included new constants and styles for citation card display.
- **Bug Fixes**
- Ensured readonly state is respected in block interactions and rendering for citation blocks.
- **Documentation**
- Added exports and effects for new citation components and features.
- **Tests**
- Updated snapshots to include citation-related properties in block data.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Closes: [BS-3302](https://linear.app/affine-design/issue/BS-3302/處理-affine-中的-redos-風險)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **Bug Fixes**
- Improved handling of footnote definitions with varied spacing, special characters, and malformed or incomplete entries, ensuring more reliable processing and display.
- **New Features**
- Introduced advanced parsing for footnote URLs to improve accuracy and validation of footnote content.
- **Tests**
- Expanded test coverage for footnote processing to include additional edge cases and mixed content scenarios, enhancing overall robustness.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Closes: [BS-3272](https://linear.app/affine-design/issue/BS-3272/footnote-适配-exa-api-返回结果)
## What's Changed
Add link preview data support (favicon, title, description) for URL references in footnotes:
- Store and display URL preview data in footnotes
- Add encoding/decoding support for favicon URLs
- Optimize link preview by using existing preview data when available
donteatfriedrice