[merynz]

What changed

• Introduces a pure, deterministic two-bone IK authoring solver with explicit failure gates for ambiguous or incomplete animator-to-deform mapping, invalid hierarchy, independent target ownership, and degenerate bones.
• IK REACH overlay integrates into qualified Studio Motion workspace. Drag a permitted end-joint handle to solve the reach and write actual user-animation keys for the mapped start/elbow animator controls; undo/sibling edit/requalification semantics remain authoritative. Unqualified/runtime-only content stays read-only.
• Preserves existing interpolation curves while re-keying and optimizes overlay redraw allocation.
• Adds a full-surface fiery plasma gradient to AWAKEN CTA with no continuous animation overhead.
• Adds numeric IK tests and CI lane.

Authority boundaries

This is a Studio authoring preview, not canonical Mechanics execution or runtime IK. Multi-segment torso/feet IK and world/view-turn continuity remain next milestones. No fake puppet/proof/compile sessions.

Rollout

Validate CI and responsive screenshots, then stage to busted-live-preview; do not merge compiler work automatically.