new: snippet for installing ServerBoxMonitor

lib/data/provider/snippet.dart

@@ -29,9 +29,19 @@ class SnippetProvider extends ChangeNotifier {
       order.removeWhere((e) => surplus.any((ele) => ele == e));
       _setting.snippetOrder.put(order);
     }
+    _addInternal();
     _updateTags();
   }
 
+  void _addInternal() {
+    if (!_setting.fTISBM.fetch()) {
+      return;
+    }
+    _snippets.add(installSBM);
+    _store.put(installSBM);
+    _setting.fTISBM.put(false);
+  }
+
   void _updateTags() {
     _tags.clear();
     final tags = <String>{};

lib/data/store/setting.dart

@@ -191,9 +191,15 @@ class SettingStore extends PersistentStore {
   );
 
   // Never show these settings for users
+  // Guide for these settings:
+  // - key should start with `_` and be shorter as possible
+  //
   // ------BEGIN------
 
   /// Version of store db
   late final storeVersion = StoreProperty(box, 'storeVersion', 0);
+
+  /// Whether is first time to add Snippet<Install ServerBoxMonitor>
+  late final fTISBM = StoreProperty(box, '_fTISBM', true);
   // ------END------
 }