style(web): keep market tag filter on a single horizontal-scroll row

With many category tags the quick-filter row used `sm:flex-wrap` on
desktop, so once tags overflowed the available width they wrapped onto a
second, center-aligned line — leaving an orphan tag floating under the
row (looked broken and only gets worse as more tags are added).

Make the row a single, never-wrapping line that scrolls horizontally at
every breakpoint, left-aligned, with the scrollbar hidden and a subtle
right-edge fade to signal there's more to scroll. Adds a reusable
`.scrollbar-hide` utility to global.css.

web/src/app/global.css

@@ -74,6 +74,15 @@
   }
 }
 
+/* Hide scrollbar while keeping scroll behaviour (horizontal tag/filter rows). */
+.scrollbar-hide {
+  -ms-overflow-style: none; /* IE / Edge */
+  scrollbar-width: none; /* Firefox */
+}
+.scrollbar-hide::-webkit-scrollbar {
+  display: none; /* Chrome / Safari / WebKit */
+}
+
 @custom-variant dark (&:is(.dark *));
 
 @theme inline {