intro backdrop + object-text linkage: establishing shot anchored below the copy (parallax, disabled under reduced motion); each legend row focuses its own part - the scrub walks the list and the described object stands out while the rest sit back, hover/keyboard pins the link

build.sh

@@ -20,7 +20,8 @@ for f in pilot/arc.tpl.html pilot/manifest-docker.json pilot/manifest-cluster.js
          assets/dist/delivery-flow.svg assets/dist/docker-layers.webp \
          assets/dist/course-II-cluster.webp assets/dist/course-00-surround.webp \
          assets/dist/course-III-node.webp assets/dist/course-III-pod.webp \
-         assets/dist/course-IV-traffic.webp assets/dist/course-V-orbit.webp; do
+         assets/dist/course-IV-traffic.webp assets/dist/course-V-orbit.webp \
+         assets/dist/intro-establishing.webp; do
   [[ -f "$f" ]] || { printf 'missing source: %s\n' "$f" >&2; exit 1; }
 done