Add the free-weight canon and bodyweight staples (16 exercises)

Squat/lunge: Barbell Squat, Goblet Squat, Bodyweight Squat, Lunge.
Bench station: Bench Press, Incline Bench Press, Dumbbell Bench Press,
Dumbbell Fly (the fly authors the face-on camera for its frontal arc).
Dumbbell rack: Dumbbell Row, Dumbbell Shoulder Press, Dumbbell Curl,
Lateral Raise - first uses of the dumbbell prop. Bodyweight: Push-Up,
Pull-Up, Crunch, Dip.

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

Exercise Library/Dumbbell Shoulder Press/info.md

@@ -0,0 +1,37 @@
+# Dumbbell Shoulder Press
+
+The overhead press with dumbbells — seated against an upright bench,
+press from the shoulders to lockout overhead.
+
+- **Category:** Main circuit
+- **Type:** Free-weight vertical press (dumbbells)
+- **Targets:** Shoulders, triceps, upper chest
+- **Prescription:** 3 × 8–12
+
+## Setup
+
+Set the bench back upright. Sit with the dumbbells at shoulder height,
+palms forward, forearms vertical, feet planted.
+
+## Execution
+
+1. Press both dumbbells straight up until the arms lock out overhead.
+2. Keep the weights over the shoulders — not drifting forward.
+3. Lower under control back to shoulder height.
+
+## Cues
+
+- Forearms vertical from every angle, wrists stacked over elbows.
+- Ribs down; the back stays on the pad, not arching off it.
+- The head moves slightly through at the top — bar path stays vertical.
+
+## Common Mistakes
+
+- Overarching the lower back to press bigger weights.
+- Stopping short of lockout.
+- Letting the dumbbells drift out sideways on the way up.
+
+## Progression
+
+Add weight while the back stays quiet on the pad; standing presses
+recruit more trunk once the seated pattern is strong.