Ship the 47-exercise library in-app: export, fixtures, tests, docs

render.py --export bundles the 25 new motion rigs and info pages;
figure-fixtures.json regenerated for all 47 (the Swift solver reproduces
every new motion, including negative-y pins and the new prop uses). The
fixture count assertion moves to 47, and the no-bundled-motion test now
uses Treadmill - a permanent COVERAGE.md exclusion - since Bench Press
exists. 48 tests green; watch target builds. Coverage handoff complete -
TODO-coverage.md retired.

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

Workouts/Resources/ExerciseMotions/Crunch.info.md

@@ -0,0 +1,38 @@
+# Crunch
+
+The floor ab curl — peel the shoulder blades off the mat, squeeze, and
+lower. Short range, all abs.
+
+- **Category:** Main circuit
+- **Type:** Spinal flexion (upper)
+- **Targets:** Rectus abdominis
+- **Prescription:** 3 × 15–20, slow
+
+## Setup
+
+Lie on your back, knees bent, feet flat. Fingertips lightly behind the
+ears, elbows wide.
+
+## Execution
+
+1. Exhale and curl the ribs toward the pelvis until the shoulder blades
+   leave the floor.
+2. Squeeze the abs hard at the top for a beat.
+3. Lower the shoulders back down without letting the head rest.
+
+## Cues
+
+- It's a curl, not a sit-up — the lower back stays on the mat.
+- Chin off the chest; the hands never pull the head.
+- Exhale on the way up to deepen the contraction.
+
+## Common Mistakes
+
+- Yanking the neck with the hands.
+- Sitting all the way up with the hip flexors.
+- Racing through reps with momentum.
+
+## Progression
+
+Slow the tempo and add a pause at the top; hold a small plate on the
+chest, or move to the Abdominal machine for stack-loaded flexion.