[robotic_grounding] enable object orientation tracking for ReconBody

[Arkitect-z]

Summary

• Enable the existing motion_object_orientation_error_exp primitive in G1SonicReconBodyRewardsCfg.
• Add a focused regression test for the position/orientation composition and active runtime reward manager.
• Keep the existing object-position reward unchanged.

Rationale

ReconBody already tracks object position, while the repository's existing object-orientation primitive is not included in its reward composition. The CHORD paper describes the task objective as tracking object pose in SE(3).

This change uses two independent exponential kernels:

exp(-||delta_position||^2 / 0.2^2) + exp(-theta^2 / 0.4^2).

It therefore aligns ReconBody with the paper's object-pose objective, but it is not a formula-level reproduction of the paper's single joint SE(3) exponential kernel.

Adding the proposed weight = 1.0 term raises the maximum object-pose reward contribution from 1.0 to 2.0 when both errors are zero. The paper does not specify this weight or std = 0.4: the weight is proposed for consistency with the existing position and orientation-tracking term weights, and the standard deviation is inferred from the existing ReconBody anchor and end-effector orientation kernels. Maintainer confirmation of both values is requested.

Scope

• Keeps motion_object_position_error_exp with its existing function, weight = 1.0, and std = 0.2.
• Reuses the existing official orientation primitive without changing its mathematics.
• Does not change observations, actions, resets, curriculum, VOC, terminations, or any other reward.
• Adds no dependency, private task, private path, data, asset, checkpoint, generated output, or object/task-specific special case.
• This is a general ReconBody configuration fix.

Test plan

• robotic_grounding/** component pre-commit passed.
• Changed-file pre-commit passed.
• git diff --check passed.
• python3 -m compileall -q robotic_grounding/source passed.
• Static composition assertions passed.

Checklist

• Commit is signed off under the configured contributor identity.
• Tests were added for the behavior change.
• No documentation change is needed because the existing primitive reward table already documents object-orientation tracking; this PR only enables its ReconBody composition.