Each enemy is a Transform-only root with a
body child (rotates to face you, on the world layer). Nameplates
and health bars are independent entities tracked via
ScreenFollow: each frame it projects the enemy's world
position through the camera and writes the screen coord to the UI entity's
Transform. A UIPanel with
positioning: "transform" on the screen-space UI layer reads
that coord — so the UI tracks the enemy while staying axis-aligned and
constant-size as the camera zooms and rotates.