Add tools and tests for AnyImage model management and documentation

- Implement sync_models.py for preparing and uploading ONNX artifacts.
- Create build_node.py for building and validating Blender scripts.
- Add docs.py for building and previewing documentation with Mike or MkDocs.
- Introduce model_exports.py for exporting PyTorch models to ONNX format.
- Develop pack.py for packaging the project with dependencies for different platforms.
- Add test_sync_models.py to validate sync_models functionality.
- Add test_tool_commands.py to ensure repository tools have correct command scripts.
- Initialize tools package with __init__.py.

docs/internals/operators/index.md

@@ -1,6 +1,6 @@
 # Operator 实现索引
 
-`src/anyimage/operators/` 负责 Blender 侧交互、Job 请求组装和结果导入。内部实现按完整功能包或顶层业务模块拆页；`common/` 的边界见[程序架构](../architecture.md)，实际公开入口见[Common 公共函数](../common.md)。
+`src/anyimage/operators/` 负责 Blender 侧交互、Job 请求组装和结果导入。
 
 | Operator 路径 | 实现页 | 主要职责 |
 | --- | --- | --- |
@@ -15,4 +15,4 @@
 | `operators/remove_background.py` | [Remove Background](remove-background.md) | BEN2 去背与结果替换 |
 | `operators/upscale.py` | [Upscale](upscale.md) | 当前 Image 的 4× 高清与输入长边检查 |
 
-`operators/__init__.py` 只聚合注册类，不承载独立业务流程。具体类的注册和逆序注销由扩展入口统一管理，整体边界见[程序架构](../architecture.md)。
+`operators/__init__.py` 聚合注册类，扩展入口按顺序注册并逆序注销。