fix: stabilize portfolio scrolling and loading

Remove skeleton swaps and deferred layout estimates, restore reveal state, and use native proximity scrolling for project cards. Also make the Docker build npm registry configurable.

src/components/scenes/Scenes.module.css

@@ -51,22 +51,6 @@
   overflow: hidden;
 }
 
-.sceneSkeleton {
-  position: absolute;
-  inset: 0;
-  background:
-    linear-gradient(100deg, transparent 24%, color-mix(in srgb, var(--bg-raised) 68%, transparent) 50%, transparent 76%),
-    var(--bg-page);
-  background-size: 200% 100%, auto;
-  animation: sceneSkeletonShimmer 1.5s ease-in-out infinite;
-}
-
-@keyframes sceneSkeletonShimmer {
-  to {
-    background-position: -200% 0, 0 0;
-  }
-}
-
 .aboutScene::after {
   content: '';
   position: absolute;
@@ -114,9 +98,3 @@
     width: 100vw;
   }
 }
-
-@media (prefers-reduced-motion: reduce) {
-  .sceneSkeleton {
-    animation: none;
-  }
-}