Keep Weapon Movement Stable When Switching to Canted Optics

When switching between the primary optic and the canted sight, the weapon should rotate between aiming positions without moving forward or backward. The stock should stay shouldered throughout the transition. Here are some good example of switching between primary and canted optics from video "Are Canted Red Dots Fast?" by T.REX ARMS, posted on 2020Feb25 <https://www.youtube.com/watch?v=vBvx1GJNUA4>. 1) Top-down shot (video timestamps 2:00 to 2:05). 2) Side-view shot (from 4:07 to 4:11 and from 4:23 to 4:28). 3) Front side-view shot (from 6:27 to 6:35). 4) Over-the-shoulder shot (from 8:17 to 8:23). Notice that the firearm does not translate forward and backward like you see in build version 80 (2026OCT), and the buttstock should not leave your shoulder well. The weapon should only rotate left and right.