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/Leg Curl/motion.json

@@ -12,7 +12,7 @@
       {"kind": "line", "pts": [[104, 150], [166, 150]], "w": 5},
       {"kind": "circle", "c": [114, 90], "r": 3.5, "fill": true, "color": "prop"}
     ]},
-    {"type": "pad", "at": ["foot_r", "foot_l"], "halfLen": 9}
+    {"type": "roller", "at": ["foot_r", "foot_l"], "side": -1, "r": 5, "back": -2}
   ],
   "frames": [
     {