update deps.

lib/view/page/server/detail.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
+import 'package:nil/nil.dart';
 import 'package:provider/provider.dart';
 import 'package:toolbox/core/extension/order.dart';
 import 'package:toolbox/data/model/server/cpu.dart';
@@ -238,7 +239,7 @@ class _ServerDetailPageState extends State<ServerDetailPage>
   }
 
   Widget _buildSwapView(Swap swap) {
-    if (swap.total == 0) return placeholder;
+    if (swap.total == 0) return nil;
     final used = swap.usedPercent * 100;
     final cached = swap.cached / swap.total * 100;
     return RoundRectCard(
@@ -394,7 +395,7 @@ class _ServerDetailPageState extends State<ServerDetailPage>
 
   Widget _buildTemperature(Temperatures temps) {
     if (temps.isEmpty) {
-      return placeholder;
+      return nil;
     }
     final List<Widget> children = [
       const Row(

lib/view/page/server/edit.dart

@@ -1,6 +1,7 @@
 import 'package:after_layout/after_layout.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
+import 'package:nil/nil.dart';
 import 'package:provider/provider.dart';
 import 'package:toolbox/core/extension/navigator.dart';
 import 'package:toolbox/view/widget/input_field.dart';
@@ -99,7 +100,7 @@ class _ServerEditPageState extends State<ServerEditPage> with AfterLayoutMixin {
     return AppBar(
       title: Text(_s.edit, style: textSize18),
       actions: [
-        widget.spi != null ? delBtn : placeholder,
+        widget.spi != null ? delBtn : nil,
       ],
     );
   }
@@ -177,8 +178,8 @@ class _ServerEditPageState extends State<ServerEditPage> with AfterLayoutMixin {
                   hint: _s.pwd,
                   onSubmitted: (_) => {},
                 )
-              : placeholder,
-          usePublicKey ? _buildKeyAuth() : placeholder
+              : nil,
+          usePublicKey ? _buildKeyAuth() : nil
         ],
       ),
     );

lib/view/page/server/tab.dart

@@ -3,6 +3,7 @@ import 'package:circle_chart/circle_chart.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/l10n.dart';
 import 'package:get_it/get_it.dart';
+import 'package:nil/nil.dart';
 import 'package:provider/provider.dart';
 import 'package:toolbox/core/extension/navigator.dart';
 import 'package:toolbox/core/extension/order.dart';
@@ -122,7 +123,7 @@ class _ServerPageState extends State<ServerPage>
   }
 
   Widget _buildTagsSwitcher(List<String> tags) {
-    if (tags.isEmpty) return placeholder;
+    if (tags.isEmpty) return nil;
     final items = <String?>[null, ...tags];
     return Container(
       height: 37,
@@ -168,7 +169,7 @@ class _ServerPageState extends State<ServerPage>
 
   Widget _buildEachServerCard(Server? si) {
     if (si == null) {
-      return placeholder;
+      return nil;
     }
     return GestureDetector(
       key: Key(si.spi.id + (_tag ?? '')),