Add validated G1 kinematic motion lab for Processing 4

[daitomanabe]

Summary

• Add Processing 4.5.6 G1 Motion Lab with retained robot meshes, source-skeleton overlay, hand trails, and explicit kinematic-only status.
• Include independently validated full A/B/C references: 1,299 original dance frames each at 40 Hz, matching the openFrameworks viewer.
• Use fixed body offsets and parent-relative quaternion interpolation to retain rigid connections.
• Reject malformed schemas, hierarchy, geometry, offsets and quaternions; add regression tests and actual rendered preview.
• Document source/model provenance, remote retargeting reproduction and separate physical limitations.

Verification

• Actual Processing builds and renders for all four sketches, plus full-data G1 hard-frame/midframe and source-overlay checks.
• Exact viewer quaternion/rigid-anchor math regression tests; invalid-input fixtures and failure-path tests.
• Independent full A/B/C pose checks pass without relaxed gates.

Safety and scope

This is not a robot controller. A separate bounded physics experiment failed its self-contact penetration gate. The persistent physics-not-validated warning remains. No robot SDK, DDS connection, policy checkpoint, hardware commands or paid cloud resources are involved. Original performance data and Unitree geometry retain their own rights; the new-code MIT license does not relicense them.