The dex-retargeting target_link_human_indices expect WebXR convention
(joint 0 = WRIST) but we were outputting OpenXR convention (joint 0 = PALM).
This caused the 5 difference vectors referencing index 0 to compute
palm-to-fingertip instead of wrist-to-fingertip, degrading tracking accuracy.
Also updates Inspire hand ranges and normalization formula.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>