uniform_parent_pose took the Y angle from asin, which loses precision within about 1e-6 degrees of
+-90. The Y angle now comes from atan2 on cos(Y), as the X and Z angles already do. The gimbal
branch and the principal-range output are unchanged.
A new test parents a static Orientation with Y 1e-6 degrees off gimbal lock under a uniform
parent. Its largest corner displacement was 3.3e-8 px before this change and 1.5e-14 px after.
Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Convert Position values and spatial tangents into the new parent space.
Preserve supported static Orientation and Scale in constant uniform
parent spaces, and convert spatial Position ease speeds for uniform
transforms. Retain the compensation and Undo/Redo regressions.
Refs #348.
Co-authored-by: Codex <codex@openai.com>