* Unified loading icon
* Removed loading icon on image block
* Fixed color of circle on loading icon
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Icons in image fallback and loading states now automatically adapt to the current theme (light or dark mode) for a more consistent visual experience.
- **Style**
- Updated loading, success, and error icons to support theming and improved their color assignments for better visibility in different themes.
- **Refactor**
- Replaced static icon usage across several components with dynamic, theme-aware icons to ensure consistent appearance throughout the app.
- Removed static SVG icon exports and replaced them with theme-aware icon functions for improved maintainability.
<!-- 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 unified loading spinner icon that adapts to light or dark themes automatically.
- **Refactor**
- Streamlined loading icon usage across the app by replacing multiple theme-based icons with a single helper function for consistent and simplified icon management.
- **Chores**
- Removed an unused dependency to improve package management.
<!-- 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 -->
fundon