阶段性合并：动画重定向、碎裂共享库、第三人称玩法、编辑器面板与 vendored ufbx

- 动画：HumanoidRig 三层架构（standard 标准槽 / dialects 方言映射 / mapper 配对），
  指/趾统一走世界增量两遍式烘焙；AnimationAttach 拆为纯算法 + facade；修正 HumanoidBasis
  行走基朝向与跨骨架去重、根运动通道
- 物理：CharacterController 角色互碰撞 / shapeOffset / 接触事件；PhysicsWorld 接触合成与
  字符冲量判定
- 渲染与材质：Model 多材质按材质拆子 mesh 与贴图路径解析、DDS 直传、GLB 内嵌纹理落盘、
  不透明通道 alpha 固定 1.0、glTF FlipUVs 对齐；SceneSerializer 支持 meshIndex 与材质覆盖
- 脚本：FractureLib 抽为共享库（HostView 桥接）、WallFracture 参数直绑、新增
  ThirdPersonCamera / Follower / WASDMove 玩法；移除 GameDirector / PlayerController / Target
- 编辑器：新增 GamepadPanel、LogPanel（LogRing），改进 Inspector / 材质 / 统计 / 视口面板
- 依赖：vendored ufbx（FBX 5.x/6.x/7.x 全版本解析，替代 assimp 对 FBX 6.1 的拒读）

Lib/ufbx/LICENSE

@@ -0,0 +1,45 @@
+MIT License
+
+Copyright (c) 2026 ufbx-python contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+---
+
+This project includes ufbx (https://github.com/ufbx/ufbx), which is licensed under the MIT License:
+
+Copyright (c) 2020-2023 Samuli Raivio
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.