fix(asset-page): fix scroll issue with LayoutBuilder and ConstrainedBox

Wrap content in LayoutBuilder + ConstrainedBox to ensure proper
scrolling behavior when content exceeds viewport height.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/mining-app/lib/presentation/pages/asset/asset_page.dart

@@ -31,12 +31,16 @@ class AssetPage extends ConsumerWidget {
       backgroundColor: Colors.white,
       body: SafeArea(
         bottom: false,
-        child: RefreshIndicator(
+        child: LayoutBuilder(
+          builder: (context, constraints) {
+            return RefreshIndicator(
               onRefresh: () async {
                 ref.invalidate(shareAccountProvider(accountSequence));
               },
               child: SingleChildScrollView(
                 physics: const AlwaysScrollableScrollPhysics(),
+                child: ConstrainedBox(
+                  constraints: BoxConstraints(minHeight: constraints.maxHeight),
                   child: Column(
                     children: [
                       // 顶部导航栏
@@ -81,6 +85,9 @@ class AssetPage extends ConsumerWidget {
                   ),
                 ),
               ),
+            );
+          },
+        ),
       ),
     );
   }