Give the figure real girdles, fix orbit pinning, add roller pads

Shoulder and pelvis widths grow to human-like proportions per profile
(shoulders wider than hips for neutral/male, reversed for female) and
are now drawn — bars across the attach points that read near-full-width
face-on and as a shoulder/hip nub in profile, so limbs visibly hang
from a torso instead of a point. Orbiting no longer re-solves IK pins
in the rotated view (pins are canvas targets in the authored camera):
the pose resolves first and the posed body rotates, which fixes hands
sticking to stale screen points mid-orbit (Cat-Cow, Bird Dog, Plank).
Leg Extension and Leg Curl swap their ankle bars for a machine roller
disc — a new `roller` prop riding the shin's press side. Fixtures
regenerated; both renderers updated in lockstep.

Claude-Session: https://claude.ai/code/session_01LEoff8bXGBS83tK1c55Mf7

Workouts/ExerciseFigure/MotionSolver.swift

@@ -159,6 +159,10 @@ struct FigureGeometry {
     var noseStart, noseEnd: CGPoint?
     /// Quadratic Bézier through pelvis → mid → neck (control = 2·mid − (pelvis+neck)/2).
     var spineStart, spineControl, spineEnd: CGPoint
+    /// Shoulder girdle and pelvis bars, drawn with the spine: left attach → center →
+    /// right attach, far offsets included so the bars meet the drawn limbs exactly.
+    var girdle: [CGPoint]
+    var pelvisBar: [CGPoint]
     /// Attach → elbow/knee → hand (arms: 3 points); hip → knee → ankle → toe (legs: 4).
     var limbs: [FigureLimb: [CGPoint]]
     /// Parts far-to-near, `"head"` always last (`"spine"`, `"arm_r"`, … then `"head"`).
@@ -452,9 +456,14 @@ enum MotionSolver {
             return (fixedRank[lhs] ?? 0) < (fixedRank[rhs] ?? 0)
         } + ["head"]
 
+        func attachPoint(_ v: Vec3, _ limb: FigureLimb) -> CGPoint {
+            scr(v, shade[limb] == .far ? off : .zero)
+        }
         let geo = FigureGeometry(
             headCenter: head, headRadius: prof.headR, noseStart: noseStart, noseEnd: noseEnd,
             spineStart: pelvis, spineControl: control, spineEnd: neckB,
+            girdle: [attachPoint(p.shoulderL, .armL), neckB, attachPoint(p.shoulderR, .armR)],
+            pelvisBar: [attachPoint(p.hipL, .legL), pelvis, attachPoint(p.hipR, .legR)],
             limbs: limbs, order: order, shade: shade)
         return (resolved, geo)
     }
@@ -500,8 +509,17 @@ struct MotionTimeline {
     }
 
     /// The drawable geometry at wall-clock `time`. `yawOffset` turns the camera past
-    /// the exercise's authored yaw — the slow-orbit presentation.
+    /// the exercise's authored yaw — the slow-orbit presentation. Pins are canvas
+    /// targets in the *authored* view, so the pose resolves there first and the posed
+    /// body is then rotated; re-pinning in a rotated view would glue hands to screen
+    /// points that no longer correspond to anything (arms visibly "stuck" mid-orbit).
     func geometry(at time: Double, yawOffset: Double = 0) -> FigureGeometry {
-        MotionSolver.frameGeometry(frame(at: time), prof: profile, cam: cam + yawOffset).1
+        let frame = frame(at: time)
+        guard yawOffset != 0 else {
+            return MotionSolver.frameGeometry(frame, prof: profile, cam: cam).1
+        }
+        var posed = MotionSolver.frameGeometry(frame, prof: profile, cam: cam).0
+        posed.pins = [:]
+        return MotionSolver.frameGeometry(posed, prof: profile, cam: cam + yawOffset).1
     }
 }