Add Wall pose: new animation + pose, wire into Player pose list

New Paintman-Wall animation and Pose_Wall asset (authored via the UMotion project) added to the Player's pose list. Player MeshPainter textureSize 1024->512.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/Models/Paintman-Wall.anim.meta

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