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 {

web/src/app/home/plugins/components/plugin-market/PluginMarketComponent.tsx

@@ -787,8 +787,9 @@ function MarketPageContent({
           </div>
         </div>
 
-        {/* 用真实标签做快速筛选 */}
+        {/* 用真实标签做快速筛选 —— 始终单行横向滚动，避免标签变多时换行错位 */}
-        <div className="mx-auto flex w-full max-w-4xl items-center gap-2 overflow-x-auto pb-1 sm:flex-wrap sm:justify-center sm:overflow-visible">
+        <div className="relative mx-auto w-full max-w-4xl">
+          <div className="scrollbar-hide flex items-center gap-2 overflow-x-auto pb-1 pr-6">
             <Button
               type="button"
               variant={selectedTags.length === 0 ? 'secondary' : 'ghost'}
@@ -820,6 +821,9 @@ function MarketPageContent({
               );
             })}
           </div>
+          {/* 右侧渐隐，提示还有更多标签可横向滚动查看 */}
+          <div className="pointer-events-none absolute right-0 top-0 bottom-1 w-8 bg-gradient-to-l from-background to-transparent" />
+        </div>
       </div>
 
       {/* Scrollable extension list section */}