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

Exercise Library/Hollow Body Hold/visual.svg

@@ -2,9 +2,11 @@
   <title>Hollow Body Hold</title>
   <line x1="16" y1="156" x2="304" y2="156" stroke="#b9bec9" stroke-width="3" stroke-linecap="round"/>
   <path id="leg_l" d="M 191.0 150.0 L 236.0 140.4 L 275.1 132.1 L 272.8 121.4" stroke="#a9afba" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
+  <path id="girdle" d="M 108.8 131.1 L 102.8 129.1 L 102.8 129.1" stroke="#0d9488" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
+  <path id="pelvisBar" d="M 191.0 150.0 L 185.0 148.0 L 185.0 148.0" stroke="#0d9488" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="spine" d="M 185.0 148.0 Q 140.6 148.4 102.8 129.1" stroke="#0d9488" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_r" d="M 102.8 129.1 L 75.6 116.5 L 48.4 103.8" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="leg_r" d="M 185.0 148.0 L 230.0 138.4 L 269.1 130.1 L 266.8 119.4" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
+  <path id="arm_r" d="M 102.8 129.1 L 75.6 116.5 L 48.4 103.8" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
   <circle id="head" cx="87.4" cy="116.3" r="10" fill="white" stroke="#3a3f4b" stroke-width="6"/>
   <line id="nose" x1="93.9" y1="108.6" x2="98.4" y2="103.3" stroke="#3a3f4b" stroke-width="4" stroke-linecap="round"/>
   <g font-family="-apple-system, Helvetica, sans-serif" font-size="11" fill="#6b7180">