feat/demo(stage-*): A motion gen for better AIRI body performance

[Lilia-Chen]

This is a place to document, discuss and summary the progress of the motion-gen related functionality.

Motion Gen Roadmap

Phase 0 — Foundations

• ACT token contract established with { emotion: { name, intensity }, cognitive, intent, motion }.
• A better acting/performance streaming system

Phase 1 — Motion Gen Service (demo)

• Add motion-gen service interface
• Wire service output into mixer as upper‑body pose layer (override/high weight).
• Keep HF‑LS speech driver as additive layer.

Milestones

• ACT token produces visible upper‑body change.

Additional context

This is an in-progress thread.

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.