feat: Formulare-Menü mit Elternbrief-Einstieg + Arbeitsblatt-Personalisierung (Nutzer-Feedback)

Neue Menü-Kategorie "Formulare" in der Menüleiste: "Elternbrief erzeugen..." öffnet
jetzt einen Schüler-Picker statt nur aus der Schülerdetailansicht erreichbar zu sein,
"Arbeitsblatt personalisieren..." ist aktiv, sobald eine einzelne Lerngruppe geöffnet
ist, und erzeugt aus einer in TemplateDesigner gebauten .lavorlage-Vorlage ein PDF je
aktivem Gruppenmitglied - über eine von den Elternbrief-Vorlagen getrennte
WorksheetTemplateStore-Bibliothek.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

LehrerApp.Desktop/Views/Groups/PersonalizeWorksheetDialog.axaml

@@ -0,0 +1,62 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+        x:Class="LehrerApp.Desktop.Views.Groups.PersonalizeWorksheetDialog"
+        x:DataType="vm:PersonalizeWorksheetDialogViewModel"
+        Title="Arbeitsblatt personalisieren"
+        Width="460" Height="620"
+        CanResize="False" WindowStartupLocation="CenterOwner">
+
+  <Grid RowDefinitions="Auto,Auto,*,Auto,Auto" Margin="24">
+
+    <StackPanel Grid.Row="0" Spacing="4" Margin="0,0,0,14">
+      <TextBlock Text="Arbeitsblatt personalisieren" Classes="dialogtitle"/>
+      <TextBlock Text="{Binding GroupName}" FontSize="12" Opacity="0.65"/>
+    </StackPanel>
+
+    <StackPanel Grid.Row="1" Spacing="10" Margin="0,0,0,14">
+      <TextBlock Text="Vorlage" FontSize="12" FontWeight="SemiBold" Opacity="0.7"/>
+      <ComboBox ItemsSource="{Binding Templates}" SelectedItem="{Binding SelectedTemplate}"
+                HorizontalAlignment="Stretch" DisplayMemberBinding="{Binding Name}"/>
+      <TextBlock Text="Noch keine Arbeitsblatt-Vorlage importiert — in den Einstellungen unter „Briefvorlagen“ eine .lavorlage-Datei aus dem Vorlagen-Designer hinzufügen."
+                 Classes="emptyhint" TextWrapping="Wrap"
+                 IsVisible="{Binding HasNoTemplates}"/>
+    </StackPanel>
+
+    <ScrollViewer Grid.Row="2">
+      <StackPanel Spacing="4">
+        <TextBlock Text="Für diese Schüler erzeugen" FontSize="12" FontWeight="SemiBold" Opacity="0.7" Margin="0,0,0,4"/>
+        <ItemsControl ItemsSource="{Binding Students}">
+          <ItemsControl.ItemTemplate>
+            <DataTemplate x:DataType="vm:WorksheetStudentChoice">
+              <CheckBox Content="{Binding FullName}" IsChecked="{Binding IsIncluded}" Margin="0,3"/>
+            </DataTemplate>
+          </ItemsControl.ItemTemplate>
+        </ItemsControl>
+
+        <ItemsControl ItemsSource="{Binding Results}" Margin="0,10,0,0" IsVisible="{Binding HasResults}">
+          <ItemsControl.ItemTemplate>
+            <DataTemplate x:DataType="vm:WorksheetGenerationResult">
+              <Grid ColumnDefinitions="20,*" Margin="0,2">
+                <TextBlock Grid.Column="0" Text="{Binding Icon}" Foreground="{Binding Color}"/>
+                <TextBlock Grid.Column="1" FontSize="12">
+                  <Run Text="{Binding StudentName}"/><Run Text=" "/><Run Text="{Binding ErrorMessage}" Foreground="#D97706"/>
+                </TextBlock>
+              </Grid>
+            </DataTemplate>
+          </ItemsControl.ItemTemplate>
+        </ItemsControl>
+      </StackPanel>
+    </ScrollViewer>
+
+    <TextBlock Grid.Row="3" Text="{Binding StatusMessage}" FontSize="12" Margin="0,10,0,0" TextWrapping="Wrap"
+               IsVisible="{Binding StatusMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+
+    <Grid Grid.Row="4" ColumnDefinitions="*,8,*" Margin="0,16,0,0">
+      <Button Grid.Column="0" Content="Schließen" HorizontalAlignment="Stretch" Click="OnClose"/>
+      <Button Grid.Column="2" Content="Erzeugen…" HorizontalAlignment="Stretch" Click="OnGenerate"
+              IsEnabled="{Binding !HasNoTemplates}"/>
+    </Grid>
+
+  </Grid>
+</Window>

LehrerApp.Desktop/Views/Groups/PersonalizeWorksheetDialog.axaml.cs

@@ -0,0 +1,25 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using Avalonia.Platform.Storage;
+using LehrerApp.Desktop.ViewModels.Groups;
+
+namespace LehrerApp.Desktop.Views.Groups;
+
+public partial class PersonalizeWorksheetDialog : Window
+{
+    public PersonalizeWorksheetDialog() => InitializeComponent();
+
+    private async void OnGenerate(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not PersonalizeWorksheetDialogViewModel vm) return;
+        var folders = await StorageProvider.OpenFolderPickerAsync(new FolderPickerOpenOptions
+        {
+            Title = "Zielordner für die personalisierten Arbeitsblätter wählen",
+            AllowMultiple = false,
+        });
+        if (folders.Count == 0) return;
+        vm.Generate(folders[0].Path.LocalPath);
+    }
+
+    private void OnClose(object? sender, RoutedEventArgs e) => Close();
+}

LehrerApp.Desktop/Views/MainWindow.axaml

@@ -40,6 +40,12 @@
         <MenuItem Header="Klassenbuchabgleich…" Click="OnCompareUntisKlassenbuch"/>
         <MenuItem Header="Hausaufgabenabgleich…" Click="OnCompareUntisHausaufgaben"/>
       </MenuItem>
+      <MenuItem Header="Formulare">
+        <MenuItem Header="Elternbrief erzeugen…" Click="OnCreateParentLetter"/>
+        <MenuItem Header="Arbeitsblatt personalisieren…" Click="OnPersonalizeWorksheet"
+                  IsEnabled="{Binding CanPersonalizeWorksheet}"
+                  ToolTip.Tip="Nur verfügbar, während eine einzelne Lerngruppe geöffnet ist"/>
+      </MenuItem>
     </Menu>
   <DrawerPage x:Name="RootDrawer"
               DrawerLength="220"

LehrerApp.Desktop/Views/MainWindow.axaml.cs

@@ -1,10 +1,17 @@
 using Avalonia.Controls;
 using Avalonia.Input;
 using Avalonia.Threading;
+using LehrerApp.Core.Interfaces;
+using LehrerApp.Core.Models;
 using LehrerApp.Desktop.Services;
 using LehrerApp.Desktop.ViewModels;
+using LehrerApp.Desktop.ViewModels.Groups;
+using LehrerApp.Desktop.ViewModels.Students;
+using LehrerApp.Desktop.Views.Groups;
+using LehrerApp.Desktop.Views.Students;
 using LehrerApp.Desktop.Views.UntisHub;
 using LehrerApp.Sync;
+using LehrerApp.Templating;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace LehrerApp.Desktop.Views;
@@ -45,6 +52,25 @@ public partial class MainWindow : Window
         await UntisHubActions.RunHausaufgabenAsync(this, App.Services.GetRequiredService<UntisHubService>());
     }
 
+    private async void OnCreateParentLetter(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
+    {
+        var picker = new StudentPickerDialog
+        { DataContext = new StudentPickerDialogViewModel(App.Services.GetRequiredService<IStudentRepository>()) };
+        if (await picker.ShowDialog<Student?>(this) is { } student)
+            await LetterDialogs.ShowCreateLetterDialogAsync(this, student);
+    }
+
+    private async void OnPersonalizeWorksheet(object? sender, Avalonia.Interactivity.RoutedEventArgs e)
+    {
+        if (DataContext is not MainWindowViewModel { CurrentGroupDetail.Group: { } group } vm) return;
+        var studentIds = vm.CurrentGroupDetail!.Students.Select(s => s.Id).ToList();
+        var dialogVm = new PersonalizeWorksheetDialogViewModel(group, studentIds,
+            App.Services.GetRequiredService<IStudentRepository>(),
+            App.Services.GetRequiredService<WorksheetTemplateStore>(),
+            App.Services.GetRequiredService<ITemplateRenderer>());
+        await new PersonalizeWorksheetDialog { DataContext = dialogVm }.ShowDialog(this);
+    }
+
     private void OnWindowKeyDown(object? sender, KeyEventArgs e)
     {
         if (DataContext is not MainWindowViewModel vm) return;

LehrerApp.Desktop/Views/Settings/SettingsView.axaml

@@ -393,6 +393,66 @@
             <Separator/>
             <TextBlock Text="Vorlagen werden mit dem separaten LehrerApp Vorlagen-Designer erstellt. Designer und Hauptapp verwenden exakt dieselbe QuestPDF-Renderingbibliothek."
                        FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+
+            <Separator Margin="0,8"/>
+            <TextBlock Text="Arbeitsblatt-Vorlagen" FontSize="15" FontWeight="SemiBold"/>
+            <TextBlock Text="Eigene Vorlagenbibliothek für „Arbeitsblatt personalisieren…“ im Formulare-Menü — getrennt von den Elternbrief-Vorlagen oben, damit sich beide Listen nicht vermischen."
+                       FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+
+            <Grid ColumnDefinitions="Auto,*" ColumnSpacing="12">
+              <Button Grid.Column="0" Content="＋ .lavorlage importieren" Click="OnImportWorksheetTemplateClick"/>
+              <TextBlock Grid.Column="1" Text="{Binding WorksheetTemplateStatus}" FontSize="12"
+                         VerticalAlignment="Center" TextWrapping="Wrap"
+                         IsVisible="{Binding WorksheetTemplateStatus, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+            </Grid>
+
+            <TextBlock Text="Noch keine Arbeitsblatt-Vorlage importiert." Classes="emptyhint"
+                       IsVisible="{Binding !WorksheetTemplateList.Count}"/>
+
+            <ItemsControl ItemsSource="{Binding WorksheetTemplateList}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate DataType="vm:LetterTemplateListItem">
+                  <Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
+                          BorderThickness="1" CornerRadius="7" Padding="14,12" Margin="0,0,0,9">
+                    <StackPanel Spacing="8">
+                      <Grid ColumnDefinitions="*,Auto,Auto,Auto">
+                        <StackPanel Grid.Column="0">
+                          <TextBlock Text="{Binding Name}" FontWeight="SemiBold" FontSize="14"/>
+                          <TextBlock FontSize="11" Opacity="0.55">
+                            <Run Text="{Binding PackageFileName}"/><Run Text=" · "/>
+                            <Run Text="{Binding ValidationSummary}"/>
+                          </TextBlock>
+                        </StackPanel>
+                        <Button Grid.Column="1" Content="Öffnen" FontSize="12" Padding="10,4"
+                                Margin="8,0,0,0" Tag="{Binding}" Click="OnOpenWorksheetTemplateClick"/>
+                        <Button Grid.Column="2" Content="Neu prüfen" FontSize="12" Padding="10,4"
+                                Margin="8,0,0,0"
+                                Command="{Binding $parent[ItemsControl].((vm:SettingsViewModel)DataContext).ValidateWorksheetTemplateCommand}"
+                                CommandParameter="{Binding}"/>
+                        <Button Grid.Column="3" Content="Löschen" FontSize="12" Padding="10,4"
+                                Margin="8,0,0,0"
+                                Command="{Binding $parent[ItemsControl].((vm:SettingsViewModel)DataContext).DeleteWorksheetTemplateCommand}"
+                                CommandParameter="{Binding}"/>
+                      </Grid>
+
+                      <ItemsControl ItemsSource="{Binding Issues}" IsVisible="{Binding HasIssues}">
+                        <ItemsControl.ItemTemplate>
+                          <DataTemplate DataType="vm:LetterTemplateIssueItem">
+                            <Grid ColumnDefinitions="24,*" Margin="0,2">
+                              <TextBlock Grid.Column="0" Text="{Binding Icon}" Foreground="{Binding Color}"/>
+                              <TextBlock Grid.Column="1" Text="{Binding Message}" Foreground="{Binding Color}"
+                                         FontSize="12" TextWrapping="Wrap"/>
+                            </Grid>
+                          </DataTemplate>
+                        </ItemsControl.ItemTemplate>
+                      </ItemsControl>
+                      <TextBlock Text="✓ Vorlage ohne Auffälligkeiten" Foreground="SeaGreen" FontSize="12"
+                                 IsVisible="{Binding HasNoIssues}"/>
+                    </StackPanel>
+                  </Border>
+                </DataTemplate>
+              </ItemsControl.ItemTemplate>
+            </ItemsControl>
           </StackPanel>
         </ScrollViewer>
       </ContentPage>

LehrerApp.Desktop/Views/Settings/SettingsView.axaml.cs

@@ -277,4 +277,26 @@ public partial class SettingsView : UserControl
         if (!File.Exists(path)) return;
         System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo(path) { UseShellExecute = true });
     }
+
+    private async void OnImportWorksheetTemplateClick(object? sender, RoutedEventArgs e)
+    {
+        var topLevel = TopLevel.GetTopLevel(this);
+        if (topLevel is null || DataContext is not SettingsViewModel vm) return;
+
+        var files = await topLevel.StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
+        {
+            Title = "LehrerApp-Arbeitsblattvorlage importieren",
+            AllowMultiple = false,
+            FileTypeFilter = [new FilePickerFileType("LehrerApp-Vorlagen") { Patterns = ["*.lavorlage"] }],
+        });
+        if (files.Count > 0) vm.ImportWorksheetTemplate(files[0].Path.LocalPath);
+    }
+
+    private void OnOpenWorksheetTemplateClick(object? sender, RoutedEventArgs e)
+    {
+        if (sender is not Button { Tag: LetterTemplateListItem item }) return;
+        var path = item.Model.PackagePath;
+        if (!File.Exists(path)) return;
+        System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo(path) { UseShellExecute = true });
+    }
 }

LehrerApp.Desktop/Views/Students/StudentDetailView.axaml.cs

@@ -8,7 +8,6 @@ using LehrerApp.Desktop.Services;
 using LehrerApp.Desktop.ViewModels.Students;
 using LehrerApp.Desktop.Views.Shared;
 using Microsoft.Extensions.DependencyInjection;
-using LehrerApp.Templating;
 
 namespace LehrerApp.Desktop.Views.Students;
 
@@ -56,16 +55,7 @@ public partial class StudentDetailView : UserControl
     {
         var owner = TopLevel.GetTopLevel(this) as Window;
         if (owner is null || DataContext is not StudentDetailViewModel { Student: { } student }) return;
-
-        var vm = new CreateLetterDialogViewModel(student,
-            App.Services.GetRequiredService<TemplateStore>(),
-            App.Services.GetRequiredService<ITemplateRenderer>(),
-            App.Services.GetRequiredService<IGroupMembershipRepository>(),
-            App.Services.GetRequiredService<IGroupRepository>());
-        var dialog = new CreateLetterDialog { DataContext = vm };
-        var path = await dialog.ShowDialog<string?>(owner);
-        if (!string.IsNullOrEmpty(path) && File.Exists(path))
-            System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo(path) { UseShellExecute = true });
+        await LetterDialogs.ShowCreateLetterDialogAsync(owner, student);
     }
 
     private void ShowAddressViewer(ContactItem contact)

LehrerApp.Desktop/Views/Students/StudentPickerDialog.axaml

@@ -0,0 +1,41 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Students"
+        xmlns:vmg="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+        x:Class="LehrerApp.Desktop.Views.Students.StudentPickerDialog"
+        x:DataType="vm:StudentPickerDialogViewModel"
+        Title="Schüler wählen"
+        Width="380" Height="480"
+        CanResize="False" WindowStartupLocation="CenterOwner">
+
+  <Grid RowDefinitions="Auto,*,Auto" Margin="24">
+
+    <StackPanel Grid.Row="0" Spacing="12" Margin="0,0,0,12">
+      <TextBlock Text="Schüler wählen" Classes="dialogtitle"/>
+      <TextBox Text="{Binding SearchText}"
+               PlaceholderText="Schüler suchen …"
+               x:Name="SearchBox"/>
+    </StackPanel>
+
+    <ListBox Grid.Row="1"
+             ItemsSource="{Binding Students}"
+             SelectedItem="{Binding SelectedStudent}"
+             BorderThickness="1">
+      <ListBox.ItemTemplate>
+        <DataTemplate x:DataType="vmg:StudentPickerItem">
+          <TextBlock Text="{Binding FullName}" Padding="4,2"/>
+        </DataTemplate>
+      </ListBox.ItemTemplate>
+    </ListBox>
+
+    <StackPanel Grid.Row="2" Spacing="12" Margin="0,16,0,0">
+      <TextBlock Text="{Binding ValidationMessage}" Foreground="Red" FontSize="12"
+                 IsVisible="{Binding ValidationMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+      <Grid ColumnDefinitions="*,8,*">
+        <Button Grid.Column="0" Content="Abbrechen" HorizontalAlignment="Stretch" Click="OnCancel"/>
+        <Button Grid.Column="2" Content="Weiter" HorizontalAlignment="Stretch" Click="OnSave"/>
+      </Grid>
+    </StackPanel>
+
+  </Grid>
+</Window>

LehrerApp.Desktop/Views/Students/StudentPickerDialog.axaml.cs

@@ -0,0 +1,25 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using LehrerApp.Desktop.ViewModels.Students;
+
+namespace LehrerApp.Desktop.Views.Students;
+
+public partial class StudentPickerDialog : Window
+{
+    public StudentPickerDialog() => InitializeComponent();
+
+    protected override void OnOpened(EventArgs e)
+    {
+        base.OnOpened(e);
+        this.FindControl<TextBox>("SearchBox")?.Focus();
+    }
+
+    private void OnSave(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not StudentPickerDialogViewModel vm) return;
+        vm.SelectCommand.Execute(null);
+        if (vm.Result is not null) Close(vm.Result);
+    }
+
+    private void OnCancel(object? sender, RoutedEventArgs e) => Close(null);
+}