style(shared-ui): remove TagStrip edge fade gradients

The 2rem linear-gradient mask at each end of the tag strip was
supposed to hint at scrollable overflow, but it cuts off the
leading + trailing tags on narrow layouts where they're already
just barely visible. Dropping both mask-image declarations lets
the pills render edge-to-edge. Overflow scrolling + hidden
scrollbar stay as they were, plus the hover-lift removal from
the previous commit.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/shared-ui/src/navigation/TagStrip.svelte

@@ -176,21 +176,6 @@
 		overflow-x: auto;
 		scrollbar-width: none;
 		-ms-overflow-style: none;
-		/* Fade edges to indicate scrollable content */
-		mask-image: linear-gradient(
-			to right,
-			transparent 0%,
-			black 2rem,
-			black calc(100% - 2rem),
-			transparent 100%
-		);
-		-webkit-mask-image: linear-gradient(
-			to right,
-			transparent 0%,
-			black 2rem,
-			black calc(100% - 2rem),
-			transparent 100%
-		);
 	}
 
 	.tag-strip-container::-webkit-scrollbar {
@@ -221,7 +206,6 @@
 
 	.tag-pill:hover {
 		background: hsl(var(--color-surface-hover, var(--color-card)));
-		transform: translateY(-1px);
 	}
 
 	.tag-pill.selected {