Drawer korrigiert, Gruppenanlegen optimiert.

LehrerApp.Desktop/Views/Groups/AddGroupDialog.axaml

@@ -10,14 +10,27 @@
   <Grid RowDefinitions="*,Auto" Margin="24">
     <StackPanel Grid.Row="0" Spacing="14">
       <TextBlock Text="Neue Lerngruppe anlegen" FontSize="18" FontWeight="SemiBold"/>
+
+      <!-- Typ: Klasse oder Kurs -->
       <StackPanel Spacing="4">
-        <TextBlock Text="Name *" FontSize="12" Opacity="0.7"/>
-        <TextBox Text="{Binding Name}" Watermark="z.B. 10E, Q1 Chemie, 5a"/>
+        <TextBlock Text="Typ *" FontSize="12" Opacity="0.7"/>
+        <ComboBox ItemsSource="{Binding TypeOptions}"
+                  SelectedItem="{Binding SelectedTypeName}"
+                  HorizontalAlignment="Stretch"/>
       </StackPanel>
+
+      <!-- Bezeichnung – Label und Placeholder reagieren auf den Typ -->
       <StackPanel Spacing="4">
-        <TextBlock Text="Fach" FontSize="12" Opacity="0.7"/>
-        <TextBox Text="{Binding Subject}" Watermark="z.B. Chemie, Mathematik"/>
+        <TextBlock Text="{Binding NameLabel}" FontSize="12" Opacity="0.7"/>
+        <TextBox Text="{Binding Name}" PlaceholderText="{Binding NameHint}"/>
       </StackPanel>
+
+      <!-- Fach – nur bei Kurs relevant -->
+      <StackPanel Spacing="4" IsVisible="{Binding IsKurs}">
+        <TextBlock Text="Fach (optional)" FontSize="12" Opacity="0.7"/>
+        <TextBox Text="{Binding Subject}" PlaceholderText="z.B. Chemie, Mathematik"/>
+      </StackPanel>
+
       <Grid ColumnDefinitions="*,12,*">
         <StackPanel Grid.Column="0" Spacing="4">
           <TextBlock Text="Klassenstufe *" FontSize="12" Opacity="0.7"/>
@@ -30,9 +43,11 @@
                     HorizontalAlignment="Stretch"/>
         </StackPanel>
       </Grid>
+
       <TextBlock Text="{Binding ValidationMessage}" Foreground="Red" FontSize="12"
                  IsVisible="{Binding ValidationMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
     </StackPanel>
+
     <Grid Grid.Row="1" ColumnDefinitions="*,8,*" Margin="0,20,0,0">
       <Button Grid.Column="0" Content="Abbrechen" HorizontalAlignment="Stretch" Click="OnCancel"/>
       <Button Grid.Column="2" Content="Anlegen"   HorizontalAlignment="Stretch" Click="OnSave"/>