Rotational Mechanics is still in progress

Start with torque as the turning effect of force, use centre of mass and support region for static balance, then carry the same rotational language into moment of inertia, rolling motion, and angular momentum.

This completion page stays public, but the completion reflection only unlocks after every concept and authored checkpoint in this track is clear on this browser. The route still reads the same local concept records and solved challenge ids, and signed-in sync keeps reusing those records instead of inventing a separate track store.