Leave carousel items unmasked under reduced motion

Plan step 12, containment.md C-05. Only the parallax half of M3's rule
was honoured: the mask was still written every frame, so items kept
growing and shrinking between the keylines. Under reduced motion the
inset, the shift and the label fade are now all zero, so every item
stays at the strategy's large size and the keylines only decide where
the row snaps. `--material-carousel-pin` went with it: with no mask
there is nothing to pin the content to.

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

resources/views/components/carousel-item.blade.php

@@ -34,7 +34,7 @@
         data-material-carousel-surface
         class="relative size-full overflow-hidden rounded-corner-xl bg-surface-container-highest text-on-surface translate-x-(--material-carousel-shift) [clip-path:inset(0_var(--material-carousel-inset,0px)_round_var(--md-sys-shape-corner-xl))]"
     >
-        <div data-material-carousel-content class="size-full translate-x-(--material-carousel-pin) [&>img]:size-full [&>img]:object-cover">
+        <div data-material-carousel-content class="size-full [&>img]:size-full [&>img]:object-cover">
             {{ $slot }}
         </div>