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

pilot/assemble-arc.py

@@ -26,6 +26,7 @@ out = (ROOT / "pilot/arc.tpl.html").read_text() \
     .replace("__MAN_GITOPS__", man("gitops")) \
     .replace("__MAN_SUPPLY__", man("supply")) \
     .replace("__MAN_HELM__", man("helm")) \
+    .replace("__HERO_INTRO__", b64("intro-establishing.webp")) \
     .replace("__HERO_SURROUND__", b64("course-00-surround.webp")) \
     .replace("__HERO_NODE__", b64("course-III-node.webp")) \
     .replace("__HERO_POD__", b64("course-III-pod.webp")) \