Closes: [BS-3439](https://linear.app/affine-design/issue/BS-3439/pdf-独立页面split-view-中的-status-组件)
Related to: [BS-3143](https://linear.app/affine-design/issue/BS-3143/更新-loading-和错误样式)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Added a dedicated error handling and reload interface for PDF attachments, allowing users to retry loading PDFs when errors occur.
- **Refactor**
- Improved PDF viewer interface with clearer loading and error states.
- Enhanced attachment type detection for better performance and maintainability.
- Streamlined attachment preview logic for more direct and efficient model retrieval.
- Simplified internal PDF metadata handling and control flow for improved clarity.
- Clarified conditional rendering logic in attachment viewer components.
- Introduced explicit loading state management and refined rendering logic in attachment pages.
- **Style**
- Updated and added styles for PDF viewer controls and error status display.
- **Tests**
- Added end-to-end tests validating PDF preview error handling and attachment not-found scenarios.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Closes: [BS-3438](https://linear.app/affine-design/issue/BS-3438/attachment-embed-view-中的-status-组件)
Closes: [BS-3447](https://linear.app/affine-design/issue/BS-3447/触发-litportal-re-render)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Introduced a visual status indicator for embedded attachments with reload capability.
- Added a new resource status component to display error messages and reload actions.
- **Improvements**
- Enhanced attachment rendering flow with reactive state and unified embed handling.
- Simplified resource state and blob URL lifecycle management.
- Added status visibility flags for PDF and video embeds.
- **Bug Fixes**
- Improved error handling and refresh support for embedded content including PDFs, videos, and audio.
- **Style**
- Added styles for the attachment embed status indicator positioning.
- **Refactor**
- Streamlined attachment and resource controller implementations for better maintainability.
- **Tests**
- Added end-to-end test verifying PDF viewer reload and re-rendering in embed mode.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Related to: [BS-3101](https://linear.app/affine-design/issue/BS-3101/pdf-embed-模式的选中框选-和点开看详情有比较大的问题)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- PDF embed preview is now enabled by default for all users, regardless of workspace sharing mode.
- **Bug Fixes**
- Improved reliability of PDF viewer interaction in tests by updating the element used for visibility checks.
- Enabled opening the PDF viewer peek view in readonly and sharing modes.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Closes: [BS-3143](https://linear.app/affine-design/issue/BS-3143/更新-attachment-错误样式)
Closes: [BS-3341](https://linear.app/affine-design/issue/BS-3341/attachment-select状态ui调整)
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Improved attachment block with unified reactive state handling for loading, errors, and downloads.
- Enhanced card layouts with modular rendering and dynamic buttons based on state.
- **Bug Fixes**
- Fixed UI state for "Embed view" action, now correctly disabled when not embedded.
- Resolved attachment card styling issues and text overflow with new utility classes.
- **Refactor**
- Streamlined attachment block rendering and state management for better performance and maintainability.
- Updated toolbar configuration for consistent parameter naming.
- Simplified embedded and open methods for improved clarity.
- Made internal functions private to reduce exported API surface.
- **Chores**
- Removed unused icon export and legacy upload tracking functions.
- Updated attachment utilities to use reactive state, added data refresh, and improved error handling.
- Refined image dimension handling for consistent resizing behavior.
- Improved test selectors to target focused attachment containers for better reliability.
- Refactored CSS to separate container and card styling and adopt theme-based colors consistently.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
