Closes: [BS-3555](https://linear.app/affine-design/issue/BS-3555/ui-attachment-loading-变量更新)
Closes: [BS-3559](https://linear.app/affine-design/issue/BS-3559/ui-图片-loading-变量更新)
### Dark
<img width="625" alt="Screenshot 2025-05-26 at 20 32 36" src="https://github.com/user-attachments/assets/93501e3d-8fc6-45f9-84a0-ac147e5c5f9f" />
### Light
<img width="623" alt="Screenshot 2025-05-26 at 20 32 25" src="https://github.com/user-attachments/assets/7d5bc128-6667-45b5-982d-dab3a22706a7" />
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Loading icons are now invoked as functions, allowing for more flexible and customizable rendering with parameters like size and progress.
- **Refactor**
- Replaced theme-dependent and static loading icon references with a unified `LoadingIcon()` component across multiple components and blocks.
- Removed legacy icon variants and simplified icon import statements, centralizing icon rendering logic.
- **Style**
- Updated styles for loading and reload buttons to use theme-aware CSS variables.
- Enlarged and repositioned loading indicators in image blocks for better visibility.
- **Bug Fixes**
- Achieved consistent loading icon rendering across various blocks and components by standardizing icon invocation.
<!-- 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**
- 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**
- Images and icons in bookmark cards are now loaded through an image proxy for improved reliability and consistency.
- Embed blocks for GitHub, Loom, and YouTube now display banner and creator images via an image proxy service for enhanced image loading.
- **Refactor**
- Simplified backend URL handling and proxy logic for images, resulting in more efficient processing and reduced complexity.
- Consolidated image proxy middleware and services into a shared adapter module for streamlined imports and improved maintainability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
DarkSky