feat: 添加日历批量操作与客户端时区感知功能，优化前端 UI 交互体验

apps/lib/features/home/ui/widgets/home_floating_header.dart

@@ -26,9 +26,9 @@ class HomeFloatingHeader extends StatelessWidget {
       key: homeFloatingHeaderKey,
       padding: const EdgeInsets.fromLTRB(
         AppSpacing.lg,
-        AppSpacing.sm,
+        AppSpacing.xs,
         AppSpacing.lg,
-        AppSpacing.sm,
+        AppSpacing.xs,
       ),
       decoration: const BoxDecoration(
         color: AppColors.homeToolbarSurface,
@@ -93,6 +93,11 @@ class _HeaderIconButton extends StatelessWidget {
   Widget build(BuildContext context) {
     return IconButton(
       visualDensity: VisualDensity.compact,
+      padding: const EdgeInsets.all(AppSpacing.xs),
+      constraints: const BoxConstraints(
+        minWidth: AppSpacing.xxl + AppSpacing.lg,
+        minHeight: AppSpacing.xxl + AppSpacing.lg,
+      ),
       onPressed: onPressed,
       icon: Icon(icon, size: AppSpacing.xxl, color: AppColors.slate900),
     );
@@ -109,6 +114,11 @@ class _MessagesButton extends StatelessWidget {
   Widget build(BuildContext context) {
     return IconButton(
       visualDensity: VisualDensity.compact,
+      padding: const EdgeInsets.all(AppSpacing.xs),
+      constraints: const BoxConstraints(
+        minWidth: AppSpacing.xxl + AppSpacing.lg,
+        minHeight: AppSpacing.xxl + AppSpacing.lg,
+      ),
       onPressed: onPressed,
       icon: Stack(
         clipBehavior: Clip.none,