refactor: enhance documentation and fix punctuation in localization strings

lib/l10n/generated/app_localizations.dart

@@ -575,7 +575,7 @@ abstract class AppLocalizations {
   /// Warning message for irreversible actions
   ///
   /// In en, this message translates to:
-  /// **'This can\'t be undone'**
+  /// **'This can\'t be undone.'**
   String get this_cannot_be_undone;
 
   /// Date format for today

lib/l10n/generated/app_localizations_de.dart

@@ -262,7 +262,7 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String get this_cannot_be_undone =>
-      'Dies kann nicht rückgängig gemacht werden';
+      'Dies kann nicht rückgängig gemacht werden.';
 
   @override
   String get today_at => 'Heute um';

lib/l10n/generated/app_localizations_en.dart

@@ -261,7 +261,7 @@ class AppLocalizationsEn extends AppLocalizations {
       'There is no group matching your search';
 
   @override
-  String get this_cannot_be_undone => 'This can\'t be undone';
+  String get this_cannot_be_undone => 'This can\'t be undone.';
 
   @override
   String get today_at => 'Today at';