Remove the grey drop-shadow peek on the Adorn label tab (CS-11331)

The Adorn label tab cast a grey `drop-shadow` filter that bled out past
its clipped/rounded corners as a grey peek. Remove it. Combined with the
1px below-card nudge, the tab reads as cleanly attached to the card.

Two of the three CS-11331 points are addressed here (grey peek and the
below-card vertical alignment). The border-radius point is left as a
deliberate design call — the tab is a separate 24px-tall flag and the
card is 10px, so force-matching the radii would make the small tab look
disproportionate — and CS-11331 stays open for it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lukemelia

packages/host/app/components/adorn/adorn-label.gts

@@ -69,7 +69,6 @@ const AdornLabel: TemplateOnlyComponent<AdornLabelSignature> = <template>
       border-radius: 0.3125rem 0 0 0.3125rem;
       clip-path: polygon(0 0, calc(100% - 0.8125rem) 0, 100% 100%, 0 100%);
       z-index: 1;
-      filter: drop-shadow(0 0.3125rem 0.5rem rgba(0, 0, 0, 0.2));
     }
     /* Mirrored polygon when the label flips below the card so the
        slope still points toward the card edge. */