feat(flutter): 统一空列表占位组件

lib/pages/discover/widgets/home_drama_grid.dart

@@ -44,14 +44,19 @@ class _HomeDramaGrid extends StatelessWidget {
 
     final dramas = categories.visibleDramas;
     if (dramas.isEmpty) {
+      final missingCategory = categories.selectedSectionMissing;
       return SliverPadding(
         padding: const EdgeInsets.fromLTRB(16, 6, 16, 24),
         sliver: SliverToBoxAdapter(
-          child: Text(
-            categories.selectedSectionMissing
+          child: EmptyState(
+            key: const Key('home-all-dramas-empty'),
+            icon: missingCategory
+                ? Icons.grid_view_rounded
+                : Icons.search_off_rounded,
+            title: missingCategory
                 ? l10n.noCategoryDramas
                 : l10n.noSearchResults,
-            style: const TextStyle(color: AppColors.muted),
+            subtitle: l10n.emptyHint,
           ),
         ),
       );