rigboy v2: Spineboy's skeleton with rigboy parts, cut at every joint #80

Rig kind: SD character (motion). Walk, run and jump are allowed for this kind.

Why. Owner direction: rigboy should be the Spineboy counterpart demo. Quotes: "리그보이 대응 데모야 일단 사람 관절 최대한 동일하게 해놓고 스파인보이에서 리그보이로 파츠만 바꾸면 되는 수준으로 작업해줘" and "관절 다 끊어서 통일".

• The skeleton: keep the human joints as close to Spineboy's as possible, so that going from Spineboy to rigboy is a parts swap.
• The joints: cut at every joint, as Spineboy is built: one rigid piece per bone.

rigboy v1 (PR #79) is one side-profile painting with three dense meshes (2297 triangles). Its legs fold at deep knee flexion, and its near and far limbs were split by four hand-placed polygons. Spineboy has 40 regions and 12 light meshes. Every limb segment is a separate, complete piece whose ends overlap under its neighbour, so a joint bends without opening a gap.

Licence basis. spineboy-pro.json's licence states the project file is public domain and may be the basis for derivative work. Spineboy's images are not redistributable for commercial use. ⇒ The skeleton, constraints and animations may be carried into the public example. No Spineboy image may be committed, and comparison media that show Spineboy stay private (HQ/owner only).

Change.

1. Skeleton. Take Spineboy's human skeleton from spineboy-pro.json (rigc ingest is the reader): hip, torso→torso2→torso3, neck, head, both thigh→shin→foot chains with the foot tips, both shoulder→upper-arm→bracer→fist chains, gun and muzzle, the hair chains, and the human IK/transform constraints (leg and foot IK, aim and shoulder). Drop the hoverboard, portal, board and exhaust bones, slots and constraints. Same bone names and hierarchy. Setup lengths and positions are rescaled to rigboy's proportions by a stated rule; record the rule and every bone that needed more than it.
2. Parts. One rigboy piece per Spineboy limb slot, joints cut: thigh, shin, foot, upper arm, bracer and fist, front and rear; torso; neck; head; hair pieces; the toy as the gun. Every piece must be complete, including the occluded rear limbs and an overlap cap past each joint, so that Spineboy's own animations open no gap.
   • A single profile painting cannot supply that (v1 measured it). Produce a parts-drawn source: separately drawn complete pieces in rigboy's look. Generation on the Nova queue is authorized; follow the queue rule, quoted verbatim: "큐 뒤에 넣는다 · 앞에 끼우기 · 순서 바꾸기 · 남의 잡 취소 금지 · 기다림이 길면 멈추고 보고".
   • Hand-placed scissors may only separate structure, never repair a gap. Record each one.
3. Animations. Play Spineboy's human animations on the swapped parts: idle, walk, run, jump, shoot, aim, idle-turn, run-to-idle, death. Carry them unchanged except for the rescale rule. Any key that had to change is a finding, reported with the reason. rigboy's own aim_dial may stay as an extra.
4. Deliverable. The rigboy example directory, as v2 beside v1 or replacing it — pick one and say why. README, credits, the allowlist and a packaged-copy RigPlayer smoke, as for feat(rigboy): add the first SD-style side-profile motion rig #79.

Bar.

• Every bone, slot-role and constraint retained from Spineboy is listed in a mapping table; the bone set differs from Spineboy's human set only where stated.
• Joint gaps: 0 open pixels between neighbouring pieces at every frame of walk, run, jump and death (the deepest flexion). Measured, plus a contact sheet of the extremes.
• Folds: 0. The gate is green.
• Private: a side-by-side, Spineboy vs rigboy, of the same frames of walk, run and shoot. HQ reads it first; it is never committed.
• Public: no Spineboy image in the tree, checked by hash against examples/spineboy/images and the atlas page.

Out of scope. The hoverboard and portal; new motions beyond Spineboy's; the site demo (rig-c.github.io#120 follows whichever version lands).