refactor(apps): 主题系统迁移至 ColorScheme + 扩展架构并支持 Dark Mode

apps/lib/features/calendar/presentation/widgets/calendar_share_dialog.dart

@@ -32,7 +32,9 @@ class CalendarShareDialog extends StatefulWidget {
     return showModalBottomSheet(
       context: context,
       isScrollControlled: true,
-      backgroundColor: Colors.transparent,
+      backgroundColor: Theme.of(
+        context,
+      ).colorScheme.surface.withValues(alpha: 0),
       builder: (context) => CalendarShareDialog(
         eventId: eventId,
         eventTitle: eventTitle,
@@ -108,13 +110,14 @@ class _CalendarShareDialogState extends State<CalendarShareDialog> {
   @override
   Widget build(BuildContext context) {
     final l10n = context.l10n;
+    final colorScheme = Theme.of(context).colorScheme;
 
     return Container(
       padding: EdgeInsets.only(
         bottom: MediaQuery.of(context).viewInsets.bottom,
       ),
       decoration: BoxDecoration(
-        color: AppColors.background,
+        color: colorScheme.surface,
         borderRadius: const BorderRadius.vertical(
           top: Radius.circular(AppRadius.lg),
         ),
@@ -200,6 +203,7 @@ class _CalendarShareDialogState extends State<CalendarShareDialog> {
     bool value,
     ValueChanged<bool>? onChanged,
   ) {
+    final colorScheme = Theme.of(context).colorScheme;
     final enabled = onChanged != null;
     return Padding(
       padding: const EdgeInsets.symmetric(vertical: AppSpacing.xs),
@@ -211,13 +215,17 @@ class _CalendarShareDialogState extends State<CalendarShareDialog> {
               children: [
                 Text(
                   title,
-                  style: TextStyle(color: enabled ? null : Colors.grey),
+                  style: TextStyle(
+                    color: enabled
+                        ? colorScheme.onSurface
+                        : colorScheme.onSurfaceVariant,
+                  ),
                 ),
                 Text(
                   description,
                   style: TextStyle(
                     fontSize: 12,
-                    color: enabled ? Colors.grey : Colors.grey.shade400,
+                    color: colorScheme.onSurfaceVariant,
                   ),
                 ),
               ],