Reveal a cut-off carousel item under reduced motion

Plan step 36 review of a149970d. Reduced motion writes a zero inset for
every item, so isMasked() never called one partly shown and a press on
an item the row cut off did nothing. It now reads the item's box against
the scrollport there, as it already did for multi-aspect, and the
browser test the rewrite added to document the gap asserts the reveal
instead (plan step 32's owed test).

A focused item's inset ring is 3px in again: Tailwind's
-outline-offset-3 is 3px, not the 12px the rewrite wrote.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9

resources/js/carousel.js

@@ -26,7 +26,8 @@
  * Under reduced motion the buttons and keys scroll instantly and nothing is masked at all: M3
  * says the parallax goes and items "should no longer expand as they come into view — all items
  * are the same size", so every item stays at the strategy's large size and the keylines only
- * decide where the row snaps.
+ * decide where the row snaps. An item is then "not fully open" when the row cuts it off, so a
+ * press or focus on it still brings it into view.
  *
  * ---------------------------------------------------------------------------------------
  * Keyline maths ported from androidx (https://github.com/androidx/androidx), commit
@@ -1218,8 +1219,10 @@ document.addEventListener('alpine:init', () => {
                     return Math.abs(state.snaps[index] - this.scrollOffset()) > 1
                 }
 
-                // Nothing masks a multi-aspect item, so "not fully open" is "cut off by the row".
-                if (state.measured) {
+                // Nothing masks a multi-aspect item, nor any item under reduced motion (render()
+                // writes a zero inset for every one), so there "not fully open" is "cut off by the
+                // row": its box reaching past the scrollport's edge.
+                if (state.measured || state.reducedMotion.matches) {
                     const row = this.$refs.scroller.getBoundingClientRect()
                     const item = state.items[index].element.getBoundingClientRect()