Author the machine exercise circuit with props and corrected hip machine motions

Fourteen Planet Fitness machine exercises join the rig library, each with
authored motion, info page, and schematic equipment via the new props layer
(scene shapes, cables, bars, pads) rendered in lockstep by render.py and the
in-app figure renderer. Abductor and Adductor are authored face-on with the
real seated machine motion — knees-bent legs swinging apart/together against
knee pads — replacing the earlier middle-split depiction. The watch target
now bundles the figure renderer and motion rigs too.

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

Exercise Library/Shoulder Press/motion.json

@@ -0,0 +1,33 @@
+{
+  "name": "Shoulder Press",
+  "primary": 2,
+  "working": ["arm_r", "arm_l"],
+  "hide": [],
+  "props": [
+    {"type": "scene", "shapes": [
+      {"kind": "line", "pts": [[116, 140], [88, 50]], "w": 8},
+      {"kind": "line", "pts": [[110, 141], [148, 141]], "w": 8},
+      {"kind": "line", "pts": [[126, 143], [126, 151]], "w": 5},
+      {"kind": "line", "pts": [[110, 151], [142, 151]], "w": 4}
+    ]},
+    {"type": "bar", "at": ["hand_r", "hand_l"], "halfLen": 10}
+  ],
+  "frames": [
+    {
+      "hold": 0.4, "tween": 1.1,
+      "root": [120, 130],
+      "spine": [110, 104], "neck": 80, "gaze": 8,
+      "arm_r": [-60, 90], "arm_l": [-60, 90],
+      "leg_r": [-25, -72], "leg_l": [-25, -72],
+      "pins": {"foot_r": [164, 151], "foot_l": [168, 152]}
+    },
+    {
+      "hold": 0.4, "tween": 1.1,
+      "root": [120, 130],
+      "spine": [110, 104], "neck": 80, "gaze": 8,
+      "arm_r": [54, 36], "arm_l": [54, 36],
+      "leg_r": [-25, -72], "leg_l": [-25, -72],
+      "pins": {"foot_r": [164, 151], "foot_l": [168, 152]}
+    }
+  ]
+}