feat: Configure preserve border edges per bone

[RamType0]

With this feature, we will no longer see holes in avatar fingers by default.

[Copilot]

Pull Request Overview

This PR implements per-bone configuration for border edge preservation during mesh simplification, specifically targeting avatar finger bone preservation to prevent holes. The key changes enable selective preservation of border edges based on bone indices rather than global settings.

• Adds bone-specific border edge preservation functionality to the mesh simplification system
• Introduces a new PreservedVertexPredicator struct to determine which vertices should be preserved based on bone indices
• Updates the NDMF cascading avatar mesh simplifier to default to preserving finger bone border edges

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Runtime/MeshSimplifierOptions.cs	Adds required imports for collections and mathematics
Runtime/MeshSimplifier.cs	Adds BitArray parameter for per-bone border edge preservation and method overloads
Runtime/MergeFactory.cs	Refactors to use PreservedVertexPredicator for vertex preservation logic
Runtime/Jobs/SimplifyJob.cs	Implements PreservedVertexPredicator struct and updates merge logic
Runtime/Jobs/ComputeMergesJob.cs	Updates job parameters to include bone-specific preservation data
Ndmf/Runtime/MeshiaCascadingAvatarMeshSimplifier.cs	Adds default finger bone preservation configuration
Ndmf/Editor/Preview/MeshiaMeshSimplifierPreviewBase.cs	Updates preview interface to support BitArray parameter
Ndmf/Editor/Preview/MeshiaMeshSimplifierPreview.cs	Updates preview implementation for new interface
Ndmf/Editor/Preview/MeshiaCascadingAvatarMeshSimplifierPreview.cs	Implements bone index mapping for avatar mesh simplifier preview
Ndmf/Editor/MeshiaCascadingAvatarMeshSimplifierRendererEntryEditor.uxml	Adds UI foldout for bone preservation settings
Ndmf/Editor/MeshiaCascadingAvatarMeshSimplifierEditor.cs	Implements UI logic for bone preservation toggles
Ndmf/Editor/Meshia.MeshSimplification.Ndmf.Editor.asmdef	Adds Unity.Mathematics dependency

Comments suppressed due to low confidence (1)

Runtime/Jobs/SimplifyJob.cs:1

• Missing space before the documentation comment. Add a newline between the closing brace and the XML documentation comment.

using System;

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