feat: 更新 H5ShellPage 以支持顶部安全区域并优化布局

lib/main.dart

@@ -549,6 +549,7 @@ class _H5ShellPageState extends State<H5ShellPage> {
   @override
   Widget build(BuildContext context) {
     final currentSlot = _currentSlot;
+    final topInset = MediaQuery.paddingOf(context).top;
     final bottomInset = MediaQuery.viewInsetsOf(context).bottom;
     final showLineSwitch = !currentSlot.showShellCover &&
         currentSlot.loadError == null &&
@@ -564,7 +565,9 @@ class _H5ShellPageState extends State<H5ShellPage> {
       },
       child: Scaffold(
         backgroundColor: Colors.white,
-        body: SafeArea(
+        body: Stack(
+          children: [
+            SafeArea(
               bottom: false,
               child: Stack(
                 children: [
@@ -575,7 +578,9 @@ class _H5ShellPageState extends State<H5ShellPage> {
                     child: IndexedStack(
                       index: _currentLineIndex,
                       children: [
-                    for (var index = 0; index < _lineSlots.length; index += 1)
+                        for (var index = 0;
+                            index < _lineSlots.length;
+                            index += 1)
                           WebViewWidget(
                             key: ValueKey<int>(index),
                             controller: _lineSlots[index].controller,
@@ -614,6 +619,15 @@ class _H5ShellPageState extends State<H5ShellPage> {
                 ],
               ),
             ),
+            Positioned(
+              top: 0,
+              left: 0,
+              right: 0,
+              height: topInset,
+              child: const ColoredBox(color: Colors.white),
+            ),
+          ],
+        ),
       ),
     );
   }