Add the remaining census stations: Pec Deck, Rear Delt Fly, cable staples

Pec Deck and Rear Delt Fly author the face-on and from-behind cameras;
Triceps Pushdown and Face Pull are the cable station's two entries per
the coverage model (cable curl/crossover are considered exclusions).

Claude-Session: https://claude.ai/code/session_01HJDQQDA9QdP8zByg43H5v3

Exercise Library/Face Pull/motion.json

@@ -0,0 +1,38 @@
+{
+  "name": "Face Pull",
+  "primary": 2,
+  "camera": {"zoom": 0.7},
+  "working": ["arm_r", "arm_l"],
+  "props": [
+    {"type": "scene", "shapes": [
+      {"kind": "circle", "c": [242, -30], "r": 4, "fill": true, "color": "prop"}
+    ]},
+    {"type": "cable", "from": [242, -30], "to": ["hand_r", "hand_l"], "w": 3}
+  ],
+  "frames": [
+    {
+      "hold": 0.4, "tween": 1.0,
+      "root": {"pos": [150, 66], "pitch": 5},
+      "spine": [0, 2],
+      "neck": 4, "head": -6,
+      "shoulder_r": 95, "elbow_r": 10,
+      "shoulder_l": 95, "elbow_l": 10,
+      "hip_r": 6, "knee_r": 8, "ankle_r": 0,
+      "hip_l": 6, "knee_l": 8, "ankle_l": 0,
+      "pins": {"foot_r": [146, 148], "foot_l": [150, 150],
+               "hand_r": [214, -24], "hand_l": [218, -22]}
+    },
+    {
+      "hold": 0.5, "tween": 1.1,
+      "root": {"pos": [150, 66], "pitch": 5},
+      "spine": [0, 2],
+      "neck": 4, "head": -6,
+      "shoulder_r": {"flexion": 95, "abduction": 15}, "elbow_r": 140,
+      "shoulder_l": {"flexion": 95, "abduction": 15}, "elbow_l": 140,
+      "hip_r": 6, "knee_r": 8, "ankle_r": 0,
+      "hip_l": 6, "knee_l": 8, "ankle_l": 0,
+      "pins": {"foot_r": [146, 148], "foot_l": [150, 150],
+               "hand_r": [170, -26], "hand_l": [174, -24]}
+    }
+  ]
+}