Remove experimental per-side branch toggles and continuity state from the urdf-loader playback solver. Keep a single lower-branch rule for all chains and update docs to reflect the stable ground-facing behavior.
Add an MJCF->URDF conversion workflow and a uv-served urdf-loader demo so the walker can be inspected outside MuJoCo. Include playback kinematics, anchor diagnostics, and docs to speed up linkage debugging in Isaac-oriented workflows.