feat(emotes): five dances, built like animation, behind a radial dial

The shared clip library ships exactly one `Dance_Loop`, and five copies of one
clip is not five dances. What the runtime does have is a procedural pose layer
over a real skeleton with spring-driven hair and cloth, which is enough — if
the motion is constructed the way an animator would construct it rather than
the way a programmer reaches for first.

Wiring sine waves to bones is that first reach, and everyone can tell. A raw
sine moves fastest through the middle and slowest at the ends by the same
amount on every channel, all in phase, forever. It floats. It has no weight, no
accent, and no sense that one part of the body is driving and the rest is
following. Four principles fix it, and all four are cheap:

  OVERLAP        the body is a chain. Hips lead, spine follows a beat later,
                 head last. One subtraction — `beat - lag * i` — and the spring
                 solver then carries it out through the hair and skirt for free,
                 because the dance layer runs before it.
  ACCENT         a dance HITS poses. `shape` bends the wave so it hangs at the
                 extremes and snaps between them, which is what a key-and-
                 breakdown pass produces by hand.
  WEIGHT         the HIPS translate, not just rotate. A body that never leaves
                 its own axis reads as a puppet on a stick.
  CONTRAST       Robot deliberately breaks all of the above — zero lag,
                 quantised motion — and reads as mechanical precisely because
                 the other four do not.

Spin spots its head: it holds a heading against the turn and whips round to
catch up, which is what a real dancer does to keep from getting dizzy and the
most recognisable thing about a turn.

The dial is a radial menu because every option is then the SAME DISTANCE from
where the pointer starts — the choice is a direction, and a direction becomes
muscle memory in a way "the fourth row down" does not. Selection is by ANGLE
alone, so a flick and a careful nudge do the same thing. HOLD to open, release
to commit; a tap too short to have aimed replays the last emote, which is what
the button did before, so the old habit still works. Pressing while already
dancing just stops — having to aim at something in order to STOP would be the
most annoying possible way to build this.

debug/dance_check.gd asserts the overlap, and getting it to measure that took
four wrong measurements, each of which is now a comment where it was made:

  - correlating the hips' TRANSLATION against the head's position relative to
    them compared two different quantities at different periods; it ranked the
    Robot, whose lag is zero by construction, as the most overlapped routine.
  - a signed scalar `angle * sign of the axis's largest component` is
    DISCONTINUOUS — as a rocking bone passes back through rest the axis flips —
    so smooth Two-Step measured a full-range jump per frame, which is exactly
    what quantised motion looks like.
  - a bone's GLOBAL rotation carries every ancestor's, so the head correlates
    with the hips at lag zero however delayed the head itself is.
  - and the hips and head are driven by different channels anyway.

Measuring two links of the SAME chain, as local rotation vectors, agrees with
the authored lag: Spin measures 9 frames against 8.4 authored, Two-Step 7
against 6.6, Robot 0. The Robot is checked on the property it actually has —
its jump per frame is 0.41 of its range against 0.03-0.06 for the others.

RigRoles is pulled out of ShooterPoseModifier so the dance layer resolves bones
the same way rather than carrying a second copy. Two copies is how a rig ends up
animating correctly under one modifier and not the other.

spawn smoke 0 failures, 11/11 movement, 21/21 weapon-hold pairs, contrast 108/108.

Co-Authored-By: Claude Opus 5 <[email protected]>

characters/rig_roles.gd

@@ -0,0 +1,56 @@
+extends Object
+class_name RigRoles
+
+## Canonical bone names -> this rig's actual bone indices.
+##
+## Pulled out of `ShooterPoseModifier._resolve` so the dance layer can use the
+## same resolution instead of carrying a second copy of it. Two copies is how a
+## rig ends up animating correctly under one modifier and not the other.
+##
+## Non-negotiable: never look a bone up by name. `tools/rig_map.py` resolves
+## every rig to ROLES and writes them to the `<model>.rig.json` sidecar, and this
+## reads that. The name fallback below exists only for a model with no sidecar,
+## and it must never be the first thing tried — four characters could not hold a
+## gun because of exactly one hardcoded spelling.
+
+## The library skeleton's spine, hips first. A rig that kept its own names maps
+## onto this through the sidecar's `spine` chain.
+const SPINE := ["DEF-hips", "DEF-spine.001", "DEF-spine.002", "DEF-spine.003"]
+
+## Everything either pose layer asks for.
+const CANONICAL := SPINE + ["DEF-neck", "DEF-head",
+	"DEF-upper_arm.R", "DEF-forearm.R", "DEF-hand.R",
+	"DEF-upper_arm.L", "DEF-forearm.L", "DEF-hand.L",
+	"DEF-thigh.R", "DEF-shin.R", "DEF-thigh.L", "DEF-shin.L"]
+
+
+## Resolve `names` against a skeleton, given the sidecar's role table.
+##
+## The spine needs its own handling because a rig that kept its own skeleton
+## names things differently AND has a different number of spine bones — Taila's
+## hips are `DEF-spine` and her head is `DEF-spine.006`, and she has no bone with
+## "neck" in its name at all. Unresolved, every lean and aim pitch silently did
+## nothing.
+static func resolve(skel: Skeleton3D, roles: Dictionary,
+		names: Array = CANONICAL) -> Dictionary:
+	var alias := {}
+	if not roles.is_empty():
+		var neck: String = roles.get("neck", "")
+		var head: String = roles.get("head", "")
+		var torso: Array = []
+		for n in roles.get("spine", []):
+			if n != neck and n != head:
+				torso.append(n)
+		for i in mini(torso.size(), SPINE.size() - 1):
+			alias[SPINE[i + 1]] = torso[i]
+
+	var idx := {}
+	for n in names:
+		# Canonical names are the role keys with the DEF- prefix, so the limbs,
+		# hips, neck and head all map straight through.
+		var actual: String = alias.get(n, roles.get(String(n).trim_prefix("DEF-"), n))
+		var b := skel.find_bone(actual)
+		if b < 0:
+			b = skel.find_bone(String(n))
+		idx[n] = b
+	return idx