Kapitel 7 abgeschlossen.

2026-08-16 00:29:01 +02:00
parent da8d2bb1da
commit f9e398b225
47 changed files with 2636 additions and 107 deletions
@@ -17,9 +17,10 @@
      <Button Content="Sortierung: Gesamt" Command="{Binding SortByTotalCommand}"/>

      <Button Content="Noten verwalten" Command="{Binding ManageStudentGradesCommand}" Margin="12,0,0,0"
-              IsVisible="{Binding SelectedRow, Converter={x:Static ObjectConverters.IsNotNull}}"/>
-      <Button Content="＋ Sammelnote" Command="{Binding CollectiveGradeCommand}"/>
-      <Button Content="Zeugnisnoten" Command="{Binding ReportGradesCommand}"/>
+              IsVisible="{Binding SelectedRow, Converter={x:Static ObjectConverters.IsNotNull}}"
+              IsEnabled="{Binding !IsReadOnly}"/>
+      <Button Content="＋ Sammelnote" Command="{Binding CollectiveGradeCommand}" IsEnabled="{Binding !IsReadOnly}"/>
+      <Button Content="Zeugnisnoten" Command="{Binding ReportGradesCommand}" IsEnabled="{Binding !IsReadOnly}"/>
    </StackPanel>

    <DataGrid Grid.Row="1"
@@ -7,7 +7,7 @@
             x:Class="LehrerApp.Desktop.Views.Groups.GroupDetailView"
             x:DataType="vm:GroupDetailViewModel">

-  <Grid RowDefinitions="Auto,*">
+  <Grid RowDefinitions="Auto,Auto,*">

    <!-- Header -->
    <Border Grid.Row="0" Padding="20,16"
@@ -22,18 +22,32 @@
          </TextBlock>
          <CheckBox Content="Ausgetretene anzeigen" IsChecked="{Binding ShowFormerStudents}"
                    VerticalAlignment="Center"/>
-          <Button Content="＋ Schüler"   Command="{Binding AddStudentCommand}"/>
+          <Button Content="＋ Schüler" Command="{Binding AddStudentCommand}" IsEnabled="{Binding IsEditable}"/>
          <Button Content="{Binding SelectedStudent.WithdrawActionLabel}"
                  Command="{Binding WithdrawStudentCommand}"
                  IsVisible="{Binding SelectedStudent, Converter={x:Static ObjectConverters.IsNotNull}}"/>
          <Button Content="Austragung zurücknehmen" Command="{Binding ReinstateStudentCommand}"
                  IsVisible="{Binding SelectedStudent.HasExitDate}"/>
-          <Button Content="＋ Klausur"   Command="{Binding AddExamCommand}"/>
+          <Button Content="＋ Klausur" Command="{Binding AddExamCommand}" IsEnabled="{Binding IsEditable}"/>
        </StackPanel>
      </Grid>
    </Border>

-    <TabbedPage Grid.Row="1" TabPlacement="Top" SelectedIndex="{Binding ActiveTabIndex}">
+    <Border Grid.Row="1" Background="#FFF3CD" BorderBrush="#D97706" BorderThickness="0,0,0,1"
+            Padding="20,10" IsVisible="{Binding IsReadOnly}">
+      <Grid ColumnDefinitions="*,Auto">
+        <StackPanel Grid.Column="0" Spacing="2">
+          <TextBlock Text="Archivierte Lerngruppe · schreibgeschützt" FontWeight="SemiBold"
+                     Foreground="#92400E"/>
+          <TextBlock Text="Alle historischen Daten bleiben sichtbar. Für Korrekturen muss die Gruppe ausdrücklich wieder aktiviert werden."
+                     FontSize="12" Foreground="#92400E" TextWrapping="Wrap"/>
+        </StackPanel>
+        <Button Grid.Column="1" Content="Gruppe wieder aktivieren"
+                Command="{Binding ReactivateGroupCommand}" Margin="16,0,0,0"/>
+      </Grid>
+    </Border>
+
+    <TabbedPage Grid.Row="2" TabPlacement="Top" SelectedIndex="{Binding ActiveTabIndex}">

      <!-- Tab: Übersicht -->
      <ContentPage Header="Übersicht">
@@ -57,6 +71,18 @@
                  CanUserResizeColumns="True"
                  Margin="0">
          <DataGrid.Columns>
+            <DataGridTemplateColumn Header="" Width="48">
+              <DataGridTemplateColumn.CellTemplate>
+                <DataTemplate x:DataType="vm:StudentSummary">
+                  <Border Width="30" Height="30" CornerRadius="15" Background="{Binding AvatarColor}"
+                          HorizontalAlignment="Center" VerticalAlignment="Center"
+                          ToolTip.Tip="{Binding AvatarTooltip}">
+                    <TextBlock Text="{Binding AvatarLabel}" Foreground="White" FontWeight="Bold"
+                               HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                  </Border>
+                </DataTemplate>
+              </DataGridTemplateColumn.CellTemplate>
+            </DataGridTemplateColumn>
            <DataGridTextColumn Header="Name"     Binding="{Binding FullName}"         Width="*"/>
            <DataGridTextColumn Header="Zeitraum" Binding="{Binding PeriodLabel}"      Width="190"/>
            <DataGridTextColumn Header="Status"   Binding="{Binding MembershipStatus}" Width="170"/>
@@ -66,6 +92,7 @@
                <DataTemplate x:DataType="vm:StudentSummary">
                  <ComboBox ItemsSource="{x:Static vm:StudentSummary.NiveauOptions}"
                            SelectedItem="{Binding NiveauName}"
+                            IsEnabled="{Binding CanEdit}"
                            HorizontalAlignment="Stretch" Margin="2"/>
                </DataTemplate>
              </DataGridTemplateColumn.CellTemplate>
@@ -83,7 +110,8 @@
      <ContentPage Header="Klausuren">
        <Grid RowDefinitions="Auto,*">
          <StackPanel Grid.Row="0" Orientation="Horizontal" Spacing="8" Margin="0,0,0,8"
-                      IsVisible="{Binding SelectedExam, Converter={x:Static ObjectConverters.IsNotNull}}">
+                      IsVisible="{Binding SelectedExam, Converter={x:Static ObjectConverters.IsNotNull}}"
+                      IsEnabled="{Binding IsEditable}">
            <Button Content="Punkte eingeben" Command="{Binding GradeExamCommand}"/>
            <Button Content="Auswertung"    Command="{Binding EvaluateExamCommand}"/>
            <Button Content="Bearbeiten"    Command="{Binding EditExamCommand}"/>
@@ -3,6 +3,7 @@ using LehrerApp.Core.Interfaces;
 using LehrerApp.Core.Models;
 using LehrerApp.Core.Services;
 using LehrerApp.Desktop.ViewModels.Groups;
+using LehrerApp.Desktop.Views.Shared;
 using Microsoft.Extensions.DependencyInjection;

 namespace LehrerApp.Desktop.Views.Groups;
@@ -24,9 +25,25 @@ public partial class GroupDetailView : UserControl
            vm.OnConfirmDeleteExam = ShowDeleteExamDialog;
            vm.OnGradeExam       = ShowGradeExamDialog;
            vm.OnEvaluateExam    = ShowEvaluateExamDialog;
+            vm.OnConfirmReactivate = ShowReactivateConfirmDialog;
        }
    }

+    private async Task<bool> ShowReactivateConfirmDialog()
+    {
+        var dialog = new ConfirmDialog
+        {
+            DataContext = new ConfirmDialogInfo
+            {
+                Title = "Archivierte Gruppe wieder aktivieren?",
+                Message = "Nach der Wiederaktivierung können historische Daten dieser Gruppe wieder verändert werden.",
+                ConfirmText = "Wieder aktivieren",
+            },
+        };
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        return owner is not null && await dialog.ShowDialog<bool>(owner);
+    }
+
    private async Task<bool> ShowAddStudentDialog()
    {
        if (DataContext is not GroupDetailViewModel vm || vm.Group is null) return false;
@@ -91,6 +91,8 @@
                <MenuFlyout>
                  <MenuItem Header="Details bearbeiten"
                            Command="{Binding EditGroupCommand}"/>
+                  <MenuItem Header="Ins nächste Schuljahr übernehmen …"
+                            Command="{Binding RollOverGroupCommand}"/>
                  <MenuItem Header="{Binding SelectedGroup.ArchiveActionLabel}"
                            Command="{Binding ToggleArchiveCommand}"/>
                  <Separator/>
@@ -15,6 +15,7 @@ public partial class GroupListView : UserControl
        {
            vm.OnAddGroup = ShowAddGroupDialog;
            vm.OnEditGroup = ShowEditGroupDialog;
+            vm.OnRollOverGroup = ShowGroupRolloverDialog;
            vm.OnConfirmDelete = ShowDeleteGroupDialog;
        }
    }
@@ -42,6 +43,23 @@ public partial class GroupListView : UserControl
            await dialog.ShowDialog<bool>(owner);
    }

+    private async Task<Guid?> ShowGroupRolloverDialog(Guid groupId)
+    {
+        var group = App.Services.GetRequiredService<LehrerApp.Core.Interfaces.IGroupRepository>()
+            .GetById(groupId);
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (group is null || owner is null) return null;
+
+        var dialogVm = new GroupRolloverDialogViewModel(group,
+            App.Services.GetRequiredService<LehrerApp.Core.Interfaces.IStudentRepository>(),
+            App.Services.GetRequiredService<LehrerApp.Core.Interfaces.IGroupMembershipRepository>(),
+            App.Services.GetRequiredService<LehrerApp.Core.Interfaces.IGradingSchemeRepository>(),
+            App.Services.GetRequiredService<LehrerApp.Core.Services.SchoolYearService>(),
+            App.Services.GetRequiredService<LehrerApp.Core.Services.GroupRolloverService>());
+        var dialog = new GroupRolloverDialog { DataContext = dialogVm };
+        return await dialog.ShowDialog<Guid?>(owner);
+    }
+
    private async Task<bool> ShowDeleteGroupDialog(GroupListItem group)
    {
        var dialog = new DeleteGroupDialog { DataContext = group.DisplayName };
@@ -0,0 +1,75 @@
+<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.GroupRolloverDialog"
+        x:DataType="vm:GroupRolloverDialogViewModel"
+        Title="Ins nächste Schuljahr übernehmen"
+        Width="650" Height="720" MinWidth="560" MinHeight="600"
+        CanResize="True" WindowStartupLocation="CenterOwner">
+  <Grid RowDefinitions="Auto,*,Auto" Margin="24,20">
+    <StackPanel Grid.Row="0" Spacing="12">
+      <TextBlock Text="Ins nächste Schuljahr übernehmen" Classes="dialogtitle"/>
+      <TextBlock Text="{Binding SourceSummary}" FontSize="12" Opacity="0.65"/>
+      <TextBlock Text="Es werden nur Gruppeneinstellungen und ausgewählte Mitgliedschaften kopiert. Noten, Klausuren, Mitarbeit, Planung und Stundenplan bleiben im alten Schuljahr."
+                 FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+
+      <Grid ColumnDefinitions="*,12,130,12,100">
+        <StackPanel Grid.Column="0" Spacing="4">
+          <TextBlock Text="Neuer Gruppenname *" FontSize="12" Opacity="0.7"/>
+          <TextBox Text="{Binding Name}"/>
+          <TextBlock Text="{Binding NameError}" Foreground="Red" FontSize="11"
+                     IsVisible="{Binding NameError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+        </StackPanel>
+        <StackPanel Grid.Column="2" Spacing="4">
+          <TextBlock Text="Zielschuljahr *" FontSize="12" Opacity="0.7"/>
+          <TextBox Text="{Binding TargetSchoolYear}" PlaceholderText="2027/28"/>
+          <TextBlock Text="{Binding SchoolYearError}" Foreground="Red" FontSize="11"
+                     IsVisible="{Binding SchoolYearError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+        </StackPanel>
+        <StackPanel Grid.Column="4" Spacing="4">
+          <TextBlock Text="Klassenstufe" FontSize="12" Opacity="0.7"/>
+          <NumericUpDown Value="{Binding GradeLevel}" Minimum="1" Maximum="13" FormatString="0"/>
+        </StackPanel>
+      </Grid>
+
+      <Grid ColumnDefinitions="*,Auto">
+        <TextBlock Grid.Column="0" Text="Schülerauswahl" FontSize="14" FontWeight="SemiBold"/>
+        <TextBlock Grid.Column="1" Text="{Binding SelectedCountText}" FontSize="12" Opacity="0.6"/>
+      </Grid>
+    </StackPanel>
+
+    <Grid Grid.Row="1" RowDefinitions="*,Auto" Margin="0,10,0,0">
+      <ListBox Grid.Row="0" ItemsSource="{Binding Students}">
+        <ListBox.ItemTemplate>
+          <DataTemplate x:DataType="vm:GroupRolloverStudentItem">
+            <Grid ColumnDefinitions="Auto,*,70" Margin="4,5">
+              <CheckBox Grid.Column="0" IsChecked="{Binding IsSelected}" IsEnabled="{Binding CanSelect}"
+                        VerticalAlignment="Center" Margin="0,0,10,0"/>
+              <StackPanel Grid.Column="1">
+                <TextBlock Text="{Binding FullName}" FontSize="13" FontWeight="SemiBold"/>
+                <TextBlock Text="{Binding MembershipStatus}" FontSize="11" Opacity="0.55"/>
+              </StackPanel>
+              <TextBlock Grid.Column="2" Text="{Binding NiveauText}" FontSize="12" Opacity="0.65"
+                         HorizontalAlignment="Center" VerticalAlignment="Center"/>
+            </Grid>
+          </DataTemplate>
+        </ListBox.ItemTemplate>
+      </ListBox>
+      <TextBlock Grid.Row="1" Text="{Binding SelectionError}" Foreground="Red" FontSize="11" Margin="0,5,0,0"
+                 IsVisible="{Binding SelectionError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+    </Grid>
+
+    <StackPanel Grid.Row="2" Spacing="10" Margin="0,14,0,0">
+      <CheckBox Content="Gruppenspezifisches Notenschema übernehmen"
+                IsChecked="{Binding CopyGradingScheme}" IsVisible="{Binding HasGradingScheme}"/>
+      <CheckBox Content="Alte Gruppe nach erfolgreicher Übernahme archivieren"
+                IsChecked="{Binding ArchiveSource}"/>
+      <TextBlock Text="{Binding GeneralError}" Foreground="Red" FontSize="12" TextWrapping="Wrap"
+                 IsVisible="{Binding GeneralError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+      <Grid ColumnDefinitions="*,10,*">
+        <Button Grid.Column="0" Content="Abbrechen" HorizontalAlignment="Stretch" Click="OnCancel"/>
+        <Button Grid.Column="2" Content="Gruppe übernehmen" HorizontalAlignment="Stretch" Click="OnSave"/>
+      </Grid>
+    </StackPanel>
+  </Grid>
+</Window>
@@ -0,0 +1,19 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using LehrerApp.Desktop.ViewModels.Groups;
+
+namespace LehrerApp.Desktop.Views.Groups;
+
+public partial class GroupRolloverDialog : Window
+{
+    public GroupRolloverDialog() => InitializeComponent();
+
+    private void OnSave(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not GroupRolloverDialogViewModel vm) return;
+        vm.SaveCommand.Execute(null);
+        if (vm.Result is not null) Close(vm.Result.Id);
+    }
+
+    private void OnCancel(object? sender, RoutedEventArgs e) => Close(null);
+}
@@ -13,19 +13,19 @@
    <Grid RowDefinitions="Auto,Auto,Auto,Auto,*">

      <Button Grid.Row="0" Content="＋ Sitzung" Command="{Binding AddSessionCommand}"
-              HorizontalAlignment="Stretch" Margin="10,10,10,6"/>
+              HorizontalAlignment="Stretch" Margin="10,10,10,6" IsEnabled="{Binding !IsReadOnly}"/>

      <StackPanel Grid.Row="1" Orientation="Horizontal" Spacing="6" Margin="10,0,10,6">
        <Button Content="Schnell Mitarbeit" Command="{Binding QuickInputCommand}"
-                HorizontalAlignment="Stretch"/>
-        <Button Content="Anw./HA" Command="{Binding StatusQuickInputCommand}"/>
+                HorizontalAlignment="Stretch" IsEnabled="{Binding !IsReadOnly}"/>
+        <Button Content="Anw./HA" Command="{Binding StatusQuickInputCommand}" IsEnabled="{Binding !IsReadOnly}"/>
      </StackPanel>

      <Button Grid.Row="2" Content="Ø Mitarbeitsnote" Command="{Binding ComputeGradeCommand}"
-              HorizontalAlignment="Stretch" Margin="10,0,10,6"/>
+              HorizontalAlignment="Stretch" Margin="10,0,10,6" IsEnabled="{Binding !IsReadOnly}"/>

      <Button Grid.Row="3" Content="Mitarbeits-Assistent" Command="{Binding OpenWizardCommand}"
-              HorizontalAlignment="Stretch" Margin="10,0,10,6"/>
+              HorizontalAlignment="Stretch" Margin="10,0,10,6" IsEnabled="{Binding !IsReadOnly}"/>

      <ListBox Grid.Row="4"
               ItemsSource="{Binding Sessions}"
@@ -68,7 +68,7 @@
              BorderThickness="0,0,0,1"
              Padding="12,8">
        <ScrollViewer HorizontalScrollBarVisibility="Disabled" MaxHeight="200">
-          <ItemsControl ItemsSource="{Binding CompetencyTagGroups}">
+          <ItemsControl ItemsSource="{Binding CompetencyTagGroups}" IsEnabled="{Binding !IsReadOnly}">
            <ItemsControl.ItemTemplate>
              <DataTemplate DataType="vm:CompetencyTagGroup">
                <StackPanel Spacing="4" Margin="0,0,0,10">
@@ -58,7 +58,7 @@ public partial class ParticipationTabView : UserControl
            {
                Header       = $"{aspect.Label}  [{AspectShortcut(i)}]",
                Width        = new DataGridLength(1, DataGridLengthUnitType.Star),
-                CellTemplate = BuildCellTemplate(idx, forCompetency: false),
+                CellTemplate = BuildCellTemplate(idx, forCompetency: false, _vm.IsReadOnly),
            });
        }

@@ -66,13 +66,13 @@ public partial class ParticipationTabView : UserControl
        {
            Header       = "HA",
            Width        = new DataGridLength(50, DataGridLengthUnitType.Pixel),
-            CellTemplate = BuildHomeworkCellTemplate(),
+            CellTemplate = BuildHomeworkCellTemplate(_vm.IsReadOnly),
        });
        grid.Columns.Add(new DataGridTemplateColumn
        {
            Header       = "Anwesenheit",
            Width        = new DataGridLength(80, DataGridLengthUnitType.Pixel),
-            CellTemplate = BuildAttendanceCellTemplate(),
+            CellTemplate = BuildAttendanceCellTemplate(_vm.IsReadOnly),
        });

        // Kompetenz-Spalten (opt-in)
@@ -85,13 +85,13 @@ public partial class ParticipationTabView : UserControl
                {
                    Header       = code,
                    Width        = new DataGridLength(80, DataGridLengthUnitType.Pixel),
-                    CellTemplate = BuildCellTemplate(idx, forCompetency: true),
+                    CellTemplate = BuildCellTemplate(idx, forCompetency: true, _vm.IsReadOnly),
                });
            }
        }
    }

-    private static IDataTemplate BuildCellTemplate(int cellIndex, bool forCompetency)
+    private static IDataTemplate BuildCellTemplate(int cellIndex, bool forCompetency, bool isReadOnly)
    {
        return new FuncDataTemplate<ParticipationStudentRow>((row, _) =>
        {
@@ -119,6 +119,7 @@ public partial class ParticipationTabView : UserControl
                    Padding  = new Avalonia.Thickness(5, 1),
                    FontSize = 11,
                    Opacity  = cell.Value == val ? 1.0 : 0.3,
+                    IsEnabled = !isReadOnly,
                };
                var capturedVal = val;
                btn.Click += (_, _) => cell.SetValue(capturedVal);
@@ -134,7 +135,7 @@ public partial class ParticipationTabView : UserControl
        });
    }

-    private static IDataTemplate BuildHomeworkCellTemplate()
+    private static IDataTemplate BuildHomeworkCellTemplate(bool isReadOnly)
    {
        return new FuncDataTemplate<ParticipationStudentRow>((row, _) =>
        {
@@ -147,6 +148,7 @@ public partial class ParticipationTabView : UserControl
                Height = 26,
                Padding = new Avalonia.Thickness(3, 1),
                Command = row.ToggleHomeworkCommand,
+                IsEnabled = !isReadOnly,
            };
            void RefreshHomework()
            {
@@ -180,7 +182,7 @@ public partial class ParticipationTabView : UserControl
        });
    }

-    private static IDataTemplate BuildAttendanceCellTemplate()
+    private static IDataTemplate BuildAttendanceCellTemplate(bool isReadOnly)
    {
        return new FuncDataTemplate<ParticipationStudentRow>((row, _) =>
        {
@@ -193,6 +195,7 @@ public partial class ParticipationTabView : UserControl
                Height = 26,
                Padding = new Avalonia.Thickness(3, 1),
                Command = row.CycleAttendanceCommand,
+                IsEnabled = !isReadOnly,
            };
            void RefreshAttendance()
            {
@@ -11,10 +11,10 @@
      <TextBlock Grid.Column="0" Text="Unterrichtseinheiten" FontSize="14" FontWeight="SemiBold"
                 VerticalAlignment="Center"/>
      <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="8">
-        <Button Content="＋ Einheit"          Command="{Binding AddUnitCommand}"/>
-        <Button Content="Bearbeiten"          Command="{Binding EditUnitCommand}"/>
+        <Button Content="＋ Einheit"          Command="{Binding AddUnitCommand}" IsEnabled="{Binding !IsReadOnly}"/>
+        <Button Content="Bearbeiten"          Command="{Binding EditUnitCommand}" IsEnabled="{Binding !IsReadOnly}"/>
        <Button Content="Als Vorlage kopieren" Command="{Binding CopyUnitCommand}"/>
-        <Button Content="Löschen"             Command="{Binding DeleteUnitCommand}"/>
+        <Button Content="Löschen"             Command="{Binding DeleteUnitCommand}" IsEnabled="{Binding !IsReadOnly}"/>
      </StackPanel>
    </Grid>

@@ -62,15 +62,16 @@
        <TextBlock Text="{Binding SelectedUnitTitleSuffix}" FontSize="14" FontWeight="SemiBold"/>
      </StackPanel>
      <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="8">
-        <Button Content="＋ Stunde"              Command="{Binding AddLessonCommand}"/>
+        <Button Content="＋ Stunde"              Command="{Binding AddLessonCommand}" IsEnabled="{Binding !IsReadOnly}"/>
        <Button Content="Serie erzeugen"         Command="{Binding GenerateLessonSeriesCommand}"
+                IsEnabled="{Binding !IsReadOnly}"
                ToolTip.Tip="Stunden für alle Termine aus dem Stundenplan im gewählten Zeitraum anlegen."/>
        <Button Content="Anzeigen"               Command="{Binding ShowLessonCommand}"
                ToolTip.Tip="Verlaufsplan schreibgeschützt und größer anzeigen — zum Mitnehmen in den Unterricht."/>
-        <Button Content="Bearbeiten"             Command="{Binding EditLessonCommand}"/>
-        <Button Content="Verschieben"            Command="{Binding MoveLessonCommand}"/>
-        <Button Content="Status → Durchgeführt"  Command="{Binding AdvanceLessonStatusCommand}"/>
-        <Button Content="Löschen"                Command="{Binding DeleteLessonCommand}"/>
+        <Button Content="Bearbeiten"             Command="{Binding EditLessonCommand}" IsEnabled="{Binding !IsReadOnly}"/>
+        <Button Content="Verschieben"            Command="{Binding MoveLessonCommand}" IsEnabled="{Binding !IsReadOnly}"/>
+        <Button Content="Status → Durchgeführt"  Command="{Binding AdvanceLessonStatusCommand}" IsEnabled="{Binding !IsReadOnly}"/>
+        <Button Content="Löschen"                Command="{Binding DeleteLessonCommand}" IsEnabled="{Binding !IsReadOnly}"/>
      </StackPanel>
    </Grid>

@@ -1,6 +1,7 @@
 <UserControl xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Settings"
+             xmlns:services="clr-namespace:LehrerApp.Core.Services;assembly=LehrerApp.Core"
             xmlns:shared="clr-namespace:LehrerApp.Desktop.Views.Shared"
             x:Class="LehrerApp.Desktop.Views.Settings.SettingsView"
             x:DataType="vm:SettingsViewModel">
@@ -270,6 +271,86 @@
        </ScrollViewer>
      </ContentPage>

+      <!-- Tab: Word-Briefvorlagen (7.1.4 / 11.5) -->
+      <ContentPage Header="Briefvorlagen">
+        <ScrollViewer>
+          <StackPanel Margin="32,20,32,28" Spacing="16" MaxWidth="760">
+            <TextBlock Text="Word-Vorlagen bleiben vollständig in Word gestaltet. Die App befüllt Inhaltssteuerelemente anhand ihres Tags und prüft die Vorlage bereits beim Import."
+                       FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+
+            <Grid ColumnDefinitions="Auto,*" ColumnSpacing="12">
+              <Button Grid.Column="0" Content="＋ DOCX-Vorlage importieren" Click="OnImportLetterTemplateClick"/>
+              <TextBlock Grid.Column="1" Text="{Binding LetterTemplateStatus}" FontSize="12"
+                         VerticalAlignment="Center" TextWrapping="Wrap"
+                         IsVisible="{Binding LetterTemplateStatus, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+            </Grid>
+
+            <TextBlock Text="Noch keine Briefvorlage importiert." Classes="emptyhint"
+                       IsVisible="{Binding !LetterTemplateList.Count}"/>
+
+            <ItemsControl ItemsSource="{Binding LetterTemplateList}">
+              <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 OriginalFileName}"/><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="OnOpenLetterTemplateClick"/>
+                        <Button Grid.Column="2" Content="Neu prüfen" FontSize="12" Padding="10,4"
+                                Margin="8,0,0,0"
+                                Command="{Binding $parent[ItemsControl].((vm:SettingsViewModel)DataContext).ValidateLetterTemplateCommand}"
+                                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).DeleteLetterTemplateCommand}"
+                                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>
+
+            <Separator/>
+            <TextBlock Text="Unterstützte Tags" FontSize="15" FontWeight="SemiBold"/>
+            <TextBlock Text="In Word: Entwicklertools → Rich-Text- oder Nur-Text-Inhaltssteuerelement → Eigenschaften → Tag. Der Titel ist frei wählbar; ausgewertet wird der Tag."
+                       FontSize="12" Opacity="0.65" TextWrapping="Wrap"/>
+            <ItemsControl ItemsSource="{Binding SupportedLetterPlaceholders}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate DataType="services:LetterPlaceholder">
+                  <Grid ColumnDefinitions="190,*" Margin="0,3">
+                    <TextBlock Grid.Column="0" Text="{Binding Tag}" FontFamily="Monospace" FontSize="12"/>
+                    <TextBlock Grid.Column="1" Text="{Binding Description}" FontSize="12" Opacity="0.7"/>
+                  </Grid>
+                </DataTemplate>
+              </ItemsControl.ItemTemplate>
+            </ItemsControl>
+          </StackPanel>
+        </ScrollViewer>
+      </ContentPage>
+
      <!-- Tab: Notenschema -->
      <ContentPage Header="Notenschema">
        <ContentPage.Resources>
@@ -91,4 +91,27 @@ public partial class SettingsView : UserControl
        var owner = TopLevel.GetTopLevel(this) as Window;
        if (owner is not null) await dialog.ShowDialog(owner);
    }
+
+    private async void OnImportLetterTemplateClick(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 = "Word-Briefvorlage importieren",
+            AllowMultiple = false,
+            FileTypeFilter = [new FilePickerFileType("Word-Dokumente") { Patterns = ["*.docx"] }],
+        });
+        if (files.Count > 0) vm.ImportLetterTemplate(files[0].Path.LocalPath);
+    }
+
+    private void OnOpenLetterTemplateClick(object? sender, RoutedEventArgs e)
+    {
+        if (sender is not Button { Tag: LetterTemplateListItem item }) return;
+        var service = App.Services.GetRequiredService<LehrerApp.Core.Services.LetterTemplateService>();
+        var path = service.GetTemplatePath(item.Model);
+        if (!File.Exists(path)) return;
+        System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo(path) { UseShellExecute = true });
+    }
 }
@@ -72,6 +72,9 @@
                      <Button Grid.Column="4" Content="×" Padding="6,2"
                              Command="{Binding RemoveCommand}" FontSize="14"/>
                    </Grid>
+                    <TextBox Text="{Binding LetterSalutation}"
+                             PlaceholderText="Briefanrede, z.B. Sehr geehrte Frau Mustermann,"
+                             FontSize="12"/>
                    <!-- Zeile 2: Telefon + E-Mail -->
                    <Grid ColumnDefinitions="*,10,*">
                      <TextBox Grid.Column="0" Text="{Binding Phone}"
@@ -28,6 +28,14 @@
          </StackPanel>
        </Grid>

+        <StackPanel Spacing="4">
+          <TextBlock Text="Briefanrede" FontSize="12" Opacity="0.7"/>
+          <TextBox Text="{Binding LetterSalutation}"
+                   PlaceholderText="z.B. Sehr geehrte Frau Mustermann,"/>
+          <TextBlock Text="Wird unverändert in Word-Vorlagen für Letter.Salutation eingesetzt."
+                     FontSize="11" Opacity="0.55" TextWrapping="Wrap"/>
+        </StackPanel>
+
        <Grid ColumnDefinitions="*,10,*">
          <StackPanel Grid.Column="0" Spacing="4">
            <TextBlock Text="Telefon" FontSize="12" Opacity="0.7"/>
@@ -0,0 +1,75 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Students"
+        x:Class="LehrerApp.Desktop.Views.Students.CreateLetterDialog"
+        x:DataType="vm:CreateLetterDialogViewModel"
+        Title="Word-Brief erstellen" Width="580" Height="650"
+        MinWidth="500" MinHeight="540" CanResize="True"
+        WindowStartupLocation="CenterOwner">
+  <Grid RowDefinitions="*,Auto" Margin="24,20">
+    <ScrollViewer Grid.Row="0" VerticalScrollBarVisibility="Auto">
+      <StackPanel Spacing="15">
+        <TextBlock Text="Word-Brief erstellen" Classes="dialogtitle"/>
+        <TextBlock FontSize="12" Opacity="0.65" TextWrapping="Wrap"
+                   Text="Die Vorlage wird vor der Erzeugung erneut geprüft. Das Original bleibt unverändert; gespeichert wird eine frei bearbeitbare DOCX-Kopie."/>
+
+        <StackPanel Spacing="4">
+          <TextBlock Text="Schüler" FontSize="12" Opacity="0.7"/>
+          <TextBlock Text="{Binding StudentName}" FontWeight="SemiBold"/>
+        </StackPanel>
+        <StackPanel Spacing="4">
+          <TextBlock Text="Vorlage *" FontSize="12" Opacity="0.7"/>
+          <ComboBox ItemsSource="{Binding Templates}" SelectedItem="{Binding SelectedTemplate}"
+                    DisplayMemberBinding="{Binding Name}" HorizontalAlignment="Stretch"/>
+          <TextBlock Text="Noch keine Vorlage. Bitte unter Einstellungen → Briefvorlagen importieren."
+                     Classes="emptyhint" IsVisible="{Binding HasNoTemplates}"/>
+        </StackPanel>
+        <StackPanel Spacing="4">
+          <TextBlock Text="Kontakt *" FontSize="12" Opacity="0.7"/>
+          <ComboBox ItemsSource="{Binding Contacts}" SelectedItem="{Binding SelectedContact}"
+                    DisplayMemberBinding="{Binding Display}" HorizontalAlignment="Stretch"/>
+          <TextBlock Text="Kein aktueller Kontakt vorhanden." Classes="emptyhint"
+                     IsVisible="{Binding HasNoContacts}"/>
+        </StackPanel>
+        <Grid ColumnDefinitions="*,12,*">
+          <StackPanel Grid.Column="0" Spacing="4">
+            <TextBlock Text="Lerngruppe" FontSize="12" Opacity="0.7"/>
+            <ComboBox ItemsSource="{Binding Groups}" SelectedItem="{Binding SelectedGroup}"
+                      DisplayMemberBinding="{Binding Display}" PlaceholderText="Optional"
+                      HorizontalAlignment="Stretch"/>
+          </StackPanel>
+          <StackPanel Grid.Column="2" Spacing="4">
+            <TextBlock Text="Briefdatum *" FontSize="12" Opacity="0.7"/>
+            <CalendarDatePicker SelectedDate="{Binding LetterDate}" HorizontalAlignment="Stretch"/>
+          </StackPanel>
+        </Grid>
+
+        <Border BorderBrush="#D97706" BorderThickness="1" CornerRadius="6" Padding="10"
+                IsVisible="{Binding HasIssues}">
+          <StackPanel Spacing="5">
+            <TextBlock Text="Vor dem Erzeugen korrigieren" FontWeight="SemiBold" Foreground="#D97706"/>
+            <ItemsControl ItemsSource="{Binding Issues}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate x:DataType="vm:LetterGenerationIssue">
+                  <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>
+          </StackPanel>
+        </Border>
+        <TextBlock Text="{Binding GenerationError}" Foreground="Red" FontSize="12" TextWrapping="Wrap"
+                   IsVisible="{Binding GenerationError, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+      </StackPanel>
+    </ScrollViewer>
+
+    <Grid Grid.Row="1" ColumnDefinitions="*,10,*" Margin="0,18,0,0">
+      <Button Grid.Column="0" Content="Abbrechen" HorizontalAlignment="Stretch" Click="OnCancel"/>
+      <Button Grid.Column="2" Content="DOCX speichern …" HorizontalAlignment="Stretch"
+              IsEnabled="{Binding CanGenerate}" Click="OnGenerate"/>
+    </Grid>
+  </Grid>
+</Window>
@@ -0,0 +1,27 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using Avalonia.Platform.Storage;
+using LehrerApp.Desktop.ViewModels.Students;
+
+namespace LehrerApp.Desktop.Views.Students;
+
+public partial class CreateLetterDialog : Window
+{
+    public CreateLetterDialog() => InitializeComponent();
+
+    private async void OnGenerate(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not CreateLetterDialogViewModel vm) return;
+        var file = await StorageProvider.SaveFilePickerAsync(new FilePickerSaveOptions
+        {
+            Title = "Word-Brief speichern",
+            SuggestedFileName = vm.SuggestedFileName,
+            DefaultExtension = "docx",
+            FileTypeChoices = [new FilePickerFileType("Word-Dokumente") { Patterns = ["*.docx"] }],
+        });
+        if (file is null || !vm.Generate(file.Path.LocalPath)) return;
+        Close(file.Path.LocalPath);
+    }
+
+    private void OnCancel(object? sender, RoutedEventArgs e) => Close(null);
+}
@@ -0,0 +1,59 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Students"
+        x:Class="LehrerApp.Desktop.Views.Students.ManageStudentDialog"
+        x:DataType="vm:ManageStudentDialogViewModel"
+        Title="Schüler verwalten"
+        Width="500" Height="500"
+        CanResize="False" WindowStartupLocation="CenterOwner">
+
+  <Grid RowDefinitions="*,Auto" Margin="24">
+    <StackPanel Grid.Row="0" Spacing="14">
+      <TextBlock Text="Schüler verwalten" Classes="dialogtitle"/>
+      <TextBlock Text="{Binding StudentName}" FontSize="15" FontWeight="SemiBold"/>
+
+      <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}"
+              CornerRadius="6" Padding="14">
+        <StackPanel Spacing="8">
+          <TextBlock Text="Deaktivieren blendet den Schüler aus den normalen Listen aus. Alle historischen Daten bleiben erhalten."
+                     TextWrapping="Wrap" FontSize="12"/>
+          <TextBlock Text="Der Schüler ist bereits deaktiviert und kann wieder aktiviert werden."
+                     TextWrapping="Wrap" FontSize="12" IsVisible="{Binding IsInactive}"/>
+        </StackPanel>
+      </Border>
+
+      <StackPanel Spacing="8" IsVisible="{Binding HasReferences}">
+        <TextBlock Text="Verknüpfte Daten" FontWeight="SemiBold"/>
+        <ItemsControl ItemsSource="{Binding ReferenceItems}">
+          <ItemsControl.ItemTemplate>
+            <DataTemplate x:DataType="vm:StudentReferenceItem">
+              <Grid ColumnDefinitions="*,Auto" Margin="0,2">
+                <TextBlock Grid.Column="0" Text="{Binding Label}"/>
+                <TextBlock Grid.Column="1" Text="{Binding CountDisplay}" FontWeight="SemiBold"/>
+              </Grid>
+            </DataTemplate>
+          </ItemsControl.ItemTemplate>
+        </ItemsControl>
+        <TextBlock Text="Eine endgültige Löschung ist deshalb gesperrt. Verwende stattdessen Deaktivieren."
+                   Foreground="#D97706" TextWrapping="Wrap" FontSize="12"/>
+      </StackPanel>
+
+      <Border IsVisible="{Binding CanDelete}" BorderBrush="#C62828" BorderThickness="1"
+              CornerRadius="6" Padding="12">
+        <TextBlock Text="Es bestehen keine Verknüpfungen. Der Schüler kann endgültig gelöscht werden. Stammdaten und Kontakte gehen dabei unwiderruflich verloren."
+                   Foreground="#C62828" TextWrapping="Wrap" FontSize="12"/>
+      </Border>
+
+      <TextBlock Text="{Binding ErrorMessage}" Foreground="Red" FontSize="12"
+                 IsVisible="{Binding ErrorMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+    </StackPanel>
+
+    <Grid Grid.Row="1" ColumnDefinitions="Auto,Auto,*,Auto" ColumnSpacing="8" Margin="0,18,0,0">
+      <Button Grid.Column="0" Content="Deaktivieren" Click="OnDeactivate" IsVisible="{Binding IsActive}"/>
+      <Button Grid.Column="0" Content="Wieder aktivieren" Click="OnReactivate" IsVisible="{Binding IsInactive}"/>
+      <Button Grid.Column="1" Content="Endgültig löschen" Click="OnDeletePermanently"
+              IsEnabled="{Binding CanDelete}"/>
+      <Button Grid.Column="3" Content="Schließen" Click="OnCancel"/>
+    </Grid>
+  </Grid>
+</Window>
@@ -0,0 +1,33 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using LehrerApp.Desktop.ViewModels.Students;
+
+namespace LehrerApp.Desktop.Views.Students;
+
+public partial class ManageStudentDialog : Window
+{
+    public ManageStudentDialog() => InitializeComponent();
+
+    private void OnDeactivate(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not ManageStudentDialogViewModel vm) return;
+        vm.DeactivateCommand.Execute(null);
+        Close(vm.Result);
+    }
+
+    private void OnReactivate(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not ManageStudentDialogViewModel vm) return;
+        vm.ReactivateCommand.Execute(null);
+        Close(vm.Result);
+    }
+
+    private void OnDeletePermanently(object? sender, RoutedEventArgs e)
+    {
+        if (DataContext is not ManageStudentDialogViewModel vm) return;
+        vm.DeletePermanentlyCommand.Execute(null);
+        if (vm.Result == StudentManagementResult.Deleted) Close(vm.Result);
+    }
+
+    private void OnCancel(object? sender, RoutedEventArgs e) => Close(StudentManagementResult.Cancelled);
+}
@@ -11,16 +11,29 @@
            BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
            BorderThickness="0,0,0,1">
      <Grid ColumnDefinitions="*,Auto">
-        <shared:PageHeader Grid.Column="0" IsVisible="{Binding !IsEditing}" Title="{Binding StudentTitle}"/>
+        <Border Grid.Column="0" Width="38" Height="38" CornerRadius="19"
+                Background="{Binding StudentAvatarColor}" HorizontalAlignment="Left"
+                ToolTip.Tip="{Binding StudentAvatarTooltip}" IsVisible="{Binding !IsEditing}">
+          <TextBlock Text="{Binding StudentAvatarLabel}" Foreground="White" FontWeight="Bold" FontSize="15"
+                     HorizontalAlignment="Center" VerticalAlignment="Center"/>
+        </Border>
+        <shared:PageHeader Grid.Column="0" Margin="50,0,0,0" IsVisible="{Binding !IsEditing}" Title="{Binding StudentTitle}"/>
        <StackPanel Grid.Column="0" Spacing="6" IsVisible="{Binding IsEditing}">
-          <Grid ColumnDefinitions="*,8,*">
+          <Grid ColumnDefinitions="*,8,*,8,170">
            <TextBox Grid.Column="0" Text="{Binding EditFirstName}" PlaceholderText="Vorname"/>
            <TextBox Grid.Column="2" Text="{Binding EditLastName}"  PlaceholderText="Nachname"/>
+            <ComboBox Grid.Column="4" ItemsSource="{Binding GenderOptions}"
+                      SelectedItem="{Binding EditGender}" PlaceholderText="Geschlecht"/>
          </Grid>
        </StackPanel>
        <StackPanel Grid.Column="1" Orientation="Horizontal" Spacing="8" VerticalAlignment="Top">
+          <TextBlock Text="{Binding StudentStatus}" VerticalAlignment="Center" Opacity="0.65"/>
+          <Button Content="Word-Brief" Command="{Binding CreateLetterCommand}"
+                  IsVisible="{Binding !IsEditing}"/>
          <Button Content="Bearbeiten" Command="{Binding StartEditCommand}"
                  IsVisible="{Binding !IsEditing}"/>
+          <Button Content="Schüler verwalten" Command="{Binding ManageStudentCommand}"
+                  IsVisible="{Binding !IsEditing}"/>
          <Button Content="Speichern"  Command="{Binding SaveEditCommand}"
                  IsVisible="{Binding IsEditing}"/>
          <Button Content="Abbrechen"  Command="{Binding CancelEditCommand}"
@@ -88,6 +101,9 @@
                                CornerRadius="4" Padding="6,2" HorizontalAlignment="Left">
                          <TextBlock Text="{Binding Relation}" FontSize="11" Opacity="0.7"/>
                        </Border>
+                        <TextBlock Text="{Binding LetterSalutation}" FontSize="11" Opacity="0.6"
+                                   TextWrapping="Wrap"
+                                   IsVisible="{Binding LetterSalutation, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
                      </StackPanel>

                      <StackPanel Grid.Column="1" Grid.Row="0" Orientation="Horizontal" Spacing="8">
@@ -23,6 +23,8 @@ public partial class StudentDetailView : UserControl
        vm.OnConfirmDeleteDocumentation = ShowDeleteDocumentationDialog;
        vm.OnSaveExportFile = SaveExportFile;
        vm.OnConductParentCall = ShowParentCallSessionDialog;
+        vm.OnManageStudent = ShowManageStudentDialog;
+        vm.OnCreateLetter = ShowCreateLetterDialog;
    }

    private async Task<Contact?> ShowContactDialog(Contact? contact)
@@ -36,6 +38,32 @@ public partial class StudentDetailView : UserControl
        return saved ? vm.Result : null;
    }

+    private async Task<StudentManagementResult> ShowManageStudentDialog(Student student)
+    {
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is null) return StudentManagementResult.Cancelled;
+
+        var vm = new ManageStudentDialogViewModel(
+            App.Services.GetRequiredService<IStudentRepository>(), student);
+        var dialog = new ManageStudentDialog { DataContext = vm };
+        return await dialog.ShowDialog<StudentManagementResult>(owner);
+    }
+
+    private async Task ShowCreateLetterDialog()
+    {
+        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<LehrerApp.Core.Services.LetterTemplateService>(),
+            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 });
+    }
+
    private void ShowAddressViewer(ContactItem contact)
    {
        if (!contact.HasAddress) return;
@@ -19,13 +19,25 @@
    </Border>
    <DockPanel Grid.Row="1">
      <TextBox DockPanel.Dock="Top" Text="{Binding SearchText}"
-               PlaceholderText="Name suchen…" Margin="16,10,16,4"/>
+               PlaceholderText="Name oder Lerngruppe suchen…" Margin="16,10,16,4"/>
      <DataGrid ItemsSource="{Binding Students}"
                SelectedItem="{Binding SelectedStudent}"
                AutoGenerateColumns="False" IsReadOnly="True"
                GridLinesVisibility="Horizontal"
                CanUserReorderColumns="False" Margin="16,4">
        <DataGrid.Columns>
+          <DataGridTemplateColumn Header="" Width="48">
+            <DataGridTemplateColumn.CellTemplate>
+              <DataTemplate x:DataType="vm:StudentListItem">
+                <Border Width="30" Height="30" CornerRadius="15" Background="{Binding AvatarColor}"
+                        HorizontalAlignment="Center" VerticalAlignment="Center"
+                        ToolTip.Tip="{Binding AvatarTooltip}">
+                  <TextBlock Text="{Binding AvatarLabel}" Foreground="White" FontWeight="Bold"
+                             HorizontalAlignment="Center" VerticalAlignment="Center"/>
+                </Border>
+              </DataTemplate>
+            </DataGridTemplateColumn.CellTemplate>
+          </DataGridTemplateColumn>
          <DataGridTextColumn Header="Name"         Binding="{Binding FullName}"    Width="*"/>
          <DataGridTextColumn Header="Geburtsdatum" Binding="{Binding DateOfBirth}" Width="130"/>
        </DataGrid.Columns>