feat(cutout): implement boundary padding for cutout textures

- Introduced a new `Boundary Padding` preference in the Cutout Tool with a default of 2 px and a configurable range of 1-4 px.
- Updated the Cutout client to establish inward mapping from the final Mask, sampling in a fixed direction and processing independent material RGBA and Depth.
- Enhanced the handling of RGBA and Depth during cutout operations, ensuring proper mapping and preservation of source data.
- Added tests to validate the new boundary padding functionality and its integration with existing cutout processes.

feat(geometry): remove overall mesh smoothing from geometry nodes

- Removed the `Smooth` input from several geometry node groups to eliminate unnecessary overall mesh smoothing.
- Retained `Smooth Weight` for depth nodes while removing it from Cutout and Relief Plane nodes.
- Ensured that boundary, normal, and fill smoothing behaviors remain intact and consistent.
- Updated tests and documentation to reflect the changes in node interfaces and behaviors.

feat(normals): scale tangent normals with depth

- Reused the existing `o_normal_reduction` attribute to adjust Tangent Normal strength based on the geometry's `Depth Scale`.
- Ensured that Tangent Normal strength is consistent with the geometry depth, preserving full strength for materials that do not provide the attribute.
- Updated tests to verify the correct behavior of normal strength adjustments in both Tangent and Object Space.

openspec/changes/remove-geometry-node-smoothing/tasks.md

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+## 1. 节点组实现
+
+- [x] 1.1 从 Cutout、Depth Cutout、Depth Plane、Depth Panorama 与 Relief Plane 删除 `Smooth` 接口及末端整体 `expand_smooth()` 调用，直接连接原有着色或输出阶段
+- [x] 1.2 从 Cutout 与 Relief Plane 删除仅服务整体 smooth 的 `Smooth Weight`，并确认三个深度节点组继续以 `Smooth Weight` 驱动边界平滑
+- [x] 1.3 检查共享 smoothing 构建函数的剩余调用，保留边界平滑所需实现并清理仅随末端整体 smooth 产生的无用代码
+
+## 2. 调用方与测试
+
+- [x] 2.1 清理 operator、节点检查工具和测试中对已删除 `Smooth` 及相应 `Smooth Weight` 的赋值与接口预期
+- [x] 2.2 更新节点组库存与布局测试，验证五个节点组不再暴露 `Smooth`，且仅三个深度节点组保留 `Smooth Weight`
+- [x] 2.3 精简整体 smooth 行为测试，并保留或补充边界平滑、法线平滑、Fill Smooth 与 smooth shading 不变的有效覆盖
+
+## 3. 资产与验证
+
+- [x] 3.1 同步 `tools/nodes` 与 `docs/internals` 中相关接口和实现说明，检查仓库内不存在失效的整体 `Smooth` 引用
+- [x] 3.2 运行 `uv run node-group build`，更新并验证 `src/anyimage/assets/O_AnyImage.blend`
+- [x] 3.3 运行相关节点与 operator 测试，检查最终差异并确认专用平滑路径仍正常