feat: add motrix config for g1 motion deploy

[Lya416]

Fixes #655

Summary

• Add Motrix PPO config for G1MotionTrackingDeploy.
• Keep core training, action scale, reward, noise, and sensor settings aligned with the MuJoCo config.
• Omit geom friction randomization for Motrix because it is not reliably supported.

Validation

• git diff --check -- conf/ppo/task/g1_motion_tracking_deploy/motrix.yaml
• uv --cache-dir /tmp/uv-cache run pytest tests/config/test_locomotion_params.py::test_ppo_g1_motion_tracking_deploy

Notes

• Training artifacts, logs, checkpoints, ONNX files, and videos are not included.

[TATP-233]

是否验证？

[Lya416]

补充验证如下：

• Motrix 训练 run：logs/rsl_rl_ppo/G1MotionTrackingDeploy/2026-06-30_15-38-03_motrix
• 训练状态：completed
• completed iterations：14999
• total env steps：368640000
• final mean reward：34.97591761112213
• best mean reward：40.72710418701172
• checkpoint：model_14999.pt

训练曲线：

补充说明：曲线放在 fork 的独立验证分支 validation/motrix-pr-artifacts-20260701，不包含在本 PR 的提交内容里。