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/Arm Curl/visual.svg

@@ -6,9 +6,11 @@
   <path d="M 164.0 70.0 L 164.0 128.0" stroke="#c5cad4" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="arm_l" d="M 140.4 41.1 L 165.0 58.3 L 184.3 35.4" stroke="#86cfc5" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="leg_l" d="M 136.0 126.0 L 179.5 111.0 L 180.0 151.0 L 191.0 150.9" stroke="#a9afba" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
+  <path id="girdle" d="M 140.4 41.1 L 134.4 39.1 L 134.4 39.1" stroke="#3a3f4b" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
+  <path id="pelvisBar" d="M 136.0 126.0 L 130.0 124.0 L 130.0 124.0" stroke="#3a3f4b" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="spine" d="M 130.0 124.0 Q 130.8 80.5 134.4 39.1" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_r" d="M 134.4 39.1 L 159.0 56.3 L 178.3 33.4" stroke="#0d9488" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="leg_r" d="M 130.0 124.0 L 173.8 110.1 L 176.0 150.0 L 187.0 149.4" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
+  <path id="arm_r" d="M 134.4 39.1 L 159.0 56.3 L 178.3 33.4" stroke="#0d9488" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
   <path d="M 181.3 40.4 L 181.3 28.4" stroke="#6b7180" stroke-width="4" stroke-linecap="round" stroke-linejoin="round"/>
   <circle id="head" cx="137.2" cy="19.3" r="10" fill="white" stroke="#3a3f4b" stroke-width="6"/>
   <line id="nose" x1="146.7" y1="22.4" x2="153.4" y2="24.6" stroke="#3a3f4b" stroke-width="4" stroke-linecap="round"/>