feat: 实现日历提醒 in-app fallback 机制及通知服务重构

apps/lib/features/auth/ui/screens/login_screen.dart

@@ -175,6 +175,9 @@ class _LoginViewState extends State<LoginView> {
       mainContent: LayoutBuilder(
         builder: (context, constraints) {
           final bottomInset = MediaQuery.of(context).viewInsets.bottom;
+          final minContentHeight = constraints.hasBoundedHeight
+              ? constraints.maxHeight
+              : AppSpacing.none;
           return SingleChildScrollView(
             padding: EdgeInsets.fromLTRB(
               AppSpacing.lg,
@@ -183,7 +186,7 @@ class _LoginViewState extends State<LoginView> {
               bottomInset + AppSpacing.lg,
             ),
             child: ConstrainedBox(
-              constraints: BoxConstraints(minHeight: constraints.maxHeight),
+              constraints: BoxConstraints(minHeight: minContentHeight),
               child: Center(
                 child: ConstrainedBox(
                   constraints: const BoxConstraints(maxWidth: 320),