Tagesflagge im Sitzplan, Leistungsüberblick mit Zielnoten-Rechner

- Mitarbeit: Tagesflagge (👑 Spitzentag / 😴 Schlaftag / ⚡ Schlechter Tag)
  je Schüler und Sitzung. Primär im Sitzplatz-Dialog (⇧1/2/3, ⇧X) mit
  Badge auf der Sitzplatz-Kachel; Fallback in der Schnelleingabe für
  Lerngruppen ohne Sitzplan.
- Noten: neuer Dialog "Überblick" in der Notenübersicht zeigt Klausuren,
  Mitarbeit- und sonstige Noten eines Schülers samt berechneter
  Zeugnisnote. Zielnoten-Rechner (ReportGradeTargetCalculator) beantwortet
  "was brauche ich noch für Note X", ein Was-wäre-wenn-Rechner simuliert
  eine zusätzliche Klausurnote. Bewerter-/Schülermodus per Umschalter im
  selben Fenster — Bewertermodus zeigt zusätzlich Kursdurchschnitt je
  Klausur und erlaubt das Bearbeiten von Mitarbeit-/Sonstige-Noten.
  Klausurverlauf als Balken-Sparkline wie die bestehende Notenentwicklung.

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

LehrerApp.Desktop/Views/Groups/StudentPerformanceOverviewDialog.axaml

@@ -0,0 +1,184 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+        xmlns:students="clr-namespace:LehrerApp.Desktop.ViewModels.Students"
+        x:Class="LehrerApp.Desktop.Views.Groups.StudentPerformanceOverviewDialog"
+        x:DataType="vm:StudentPerformanceOverviewViewModel"
+        Title="Leistungsüberblick"
+        Width="920" Height="720" MinWidth="700" MinHeight="520"
+        CanResize="True" WindowStartupLocation="CenterOwner">
+
+  <Grid RowDefinitions="Auto,Auto,*,Auto" Margin="24">
+
+    <Grid Grid.Row="0" ColumnDefinitions="*,Auto">
+      <StackPanel Grid.Column="0" Spacing="2">
+        <TextBlock Text="{Binding StudentName}" Classes="dialogtitle"/>
+        <TextBlock Text="{Binding GroupLabel}" FontSize="12" Opacity="0.6"/>
+      </StackPanel>
+      <Button Grid.Column="1" Content="{Binding ModeButtonLabel}"
+              Command="{Binding ToggleModeCommand}" VerticalAlignment="Top"
+              ToolTip.Tip="Zwischen Bewerter- und Schülermodus umschalten"/>
+    </Grid>
+
+    <StackPanel Grid.Row="1" Orientation="Horizontal" Spacing="12" Margin="0,12,0,10">
+      <StackPanel Orientation="Horizontal" Spacing="6">
+        <TextBlock Text="Zeitraum:" VerticalAlignment="Center"/>
+        <ComboBox ItemsSource="{Binding PeriodOptions}" SelectedItem="{Binding SelectedPeriod}" MinWidth="170"/>
+      </StackPanel>
+      <TextBlock Text="{Binding SchemeSummary}" FontSize="12" Opacity="0.6" VerticalAlignment="Center"
+                 IsVisible="{Binding IsTeacherMode}"/>
+    </StackPanel>
+
+    <ScrollViewer Grid.Row="2">
+      <Grid ColumnDefinitions="*,300">
+        <StackPanel Grid.Column="0" Spacing="18" Margin="0,0,16,0">
+
+          <StackPanel Spacing="6">
+            <Grid ColumnDefinitions="*,Auto">
+              <TextBlock Grid.Column="0" Text="KLAUSUREN" FontSize="11" FontWeight="Bold" Opacity="0.5"/>
+              <TextBlock Grid.Column="1" Text="{Binding ExamsAverageDisplay, StringFormat='Ø {0}'}"
+                         FontSize="12" Opacity="0.7" IsVisible="{Binding ExamsAverageDisplay, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+            </Grid>
+            <ItemsControl ItemsSource="{Binding ExamRows}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate x:DataType="vm:StudentExamRow">
+                  <Grid ColumnDefinitions="Auto,*,80,80" Margin="0,4">
+                    <TextBlock Grid.Column="0" Text="{Binding DateDisplay}" FontSize="12" Opacity="0.6" Width="80"/>
+                    <TextBlock Grid.Column="1" Text="{Binding Title}" FontSize="13"/>
+                    <TextBlock Grid.Column="2" Text="{Binding OwnGradeDisplay}" FontWeight="SemiBold"
+                               HorizontalAlignment="Right"/>
+                    <TextBlock Grid.Column="3" Text="{Binding ClassAverageDisplay}" Opacity="0.55"
+                               HorizontalAlignment="Right"
+                               IsVisible="{Binding $parent[ItemsControl].((vm:StudentPerformanceOverviewViewModel)DataContext).IsTeacherMode}"
+                               ToolTip.Tip="Kursdurchschnitt dieser Klausur"/>
+                  </Grid>
+                </DataTemplate>
+              </ItemsControl.ItemTemplate>
+            </ItemsControl>
+            <TextBlock Text="Keine Klausuren im gewählten Zeitraum." Classes="emptyhint"
+                       IsVisible="{Binding !ExamRows.Count}"/>
+
+            <ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Disabled"
+                          IsVisible="{Binding !!ExamHistory.Points.Count}">
+              <ItemsControl ItemsSource="{Binding ExamHistory.Points}">
+                <ItemsControl.ItemsPanel>
+                  <ItemsPanelTemplate><StackPanel Orientation="Horizontal" Spacing="10"/></ItemsPanelTemplate>
+                </ItemsControl.ItemsPanel>
+                <ItemsControl.ItemTemplate>
+                  <DataTemplate x:DataType="students:GradeHistoryPoint">
+                    <StackPanel Width="46" VerticalAlignment="Bottom" ToolTip.Tip="{Binding TooltipText}">
+                      <Border Classes="historybar" Height="{Binding BarHeight}" Width="16" CornerRadius="2"
+                              HorizontalAlignment="Center" VerticalAlignment="Bottom"
+                              Classes.warning="{Binding IsWarning}"/>
+                      <TextBlock Text="{Binding Value}" FontSize="11" FontWeight="SemiBold"
+                                 HorizontalAlignment="Center" Margin="0,3,0,0"/>
+                      <TextBlock Text="{Binding DateDisplay}" FontSize="9" Opacity="0.5"
+                                 HorizontalAlignment="Center"/>
+                    </StackPanel>
+                  </DataTemplate>
+                </ItemsControl.ItemTemplate>
+                <ItemsControl.Styles>
+                  <Style Selector="Border.historybar">
+                    <Setter Property="Background" Value="{DynamicResource SystemControlBackgroundAccentBrush}"/>
+                  </Style>
+                  <Style Selector="Border.historybar.warning">
+                    <Setter Property="Background" Value="#E53935"/>
+                  </Style>
+                </ItemsControl.Styles>
+              </ItemsControl>
+            </ScrollViewer>
+          </StackPanel>
+
+          <StackPanel Spacing="6">
+            <Grid ColumnDefinitions="*,Auto">
+              <TextBlock Grid.Column="0" Text="MITARBEIT" FontSize="11" FontWeight="Bold" Opacity="0.5"/>
+              <TextBlock Grid.Column="1" Text="{Binding ParticipationAverageDisplay, StringFormat='Ø {0}'}"
+                         FontSize="12" Opacity="0.7" IsVisible="{Binding ParticipationAverageDisplay, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+            </Grid>
+            <ItemsControl ItemsSource="{Binding ParticipationRows}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate x:DataType="vm:StudentSimpleGradeRow">
+                  <Grid ColumnDefinitions="Auto,*,70,Auto" Margin="0,4">
+                    <TextBlock Grid.Column="0" Text="{Binding DateDisplay}" FontSize="12" Opacity="0.6" Width="80"/>
+                    <TextBlock Grid.Column="1" Text="{Binding CategoryLabel}" FontSize="13"/>
+                    <TextBox Grid.Column="2" Text="{Binding Value}"
+                             IsVisible="{Binding $parent[ItemsControl].((vm:StudentPerformanceOverviewViewModel)DataContext).IsTeacherMode}"/>
+                    <TextBlock Grid.Column="2" Text="{Binding Value}" FontWeight="SemiBold" HorizontalAlignment="Right"
+                               IsVisible="{Binding !$parent[ItemsControl].((vm:StudentPerformanceOverviewViewModel)DataContext).IsTeacherMode}"/>
+                    <Button Grid.Column="3" Content="Speichern" Command="{Binding SaveCommand}" FontSize="11" Padding="8,3" Margin="6,0,0,0"
+                            IsVisible="{Binding $parent[ItemsControl].((vm:StudentPerformanceOverviewViewModel)DataContext).IsTeacherMode}"/>
+                  </Grid>
+                </DataTemplate>
+              </ItemsControl.ItemTemplate>
+            </ItemsControl>
+            <TextBlock Text="Keine Mitarbeitsnote im gewählten Zeitraum." Classes="emptyhint"
+                       IsVisible="{Binding !ParticipationRows.Count}"/>
+          </StackPanel>
+
+          <StackPanel Spacing="6">
+            <Grid ColumnDefinitions="*,Auto">
+              <TextBlock Grid.Column="0" Text="SONSTIGE" FontSize="11" FontWeight="Bold" Opacity="0.5"/>
+              <TextBlock Grid.Column="1" Text="{Binding OtherAverageDisplay, StringFormat='Ø {0}'}"
+                         FontSize="12" Opacity="0.7" IsVisible="{Binding OtherAverageDisplay, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+            </Grid>
+            <ItemsControl ItemsSource="{Binding OtherRows}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate x:DataType="vm:StudentSimpleGradeRow">
+                  <Grid ColumnDefinitions="Auto,*,70,Auto" Margin="0,4">
+                    <TextBlock Grid.Column="0" Text="{Binding DateDisplay}" FontSize="12" Opacity="0.6" Width="80"/>
+                    <TextBlock Grid.Column="1" Text="{Binding CategoryLabel}" FontSize="13"/>
+                    <TextBox Grid.Column="2" Text="{Binding Value}"
+                             IsVisible="{Binding $parent[ItemsControl].((vm:StudentPerformanceOverviewViewModel)DataContext).IsTeacherMode}"/>
+                    <TextBlock Grid.Column="2" Text="{Binding Value}" FontWeight="SemiBold" HorizontalAlignment="Right"
+                               IsVisible="{Binding !$parent[ItemsControl].((vm:StudentPerformanceOverviewViewModel)DataContext).IsTeacherMode}"/>
+                    <Button Grid.Column="3" Content="Speichern" Command="{Binding SaveCommand}" FontSize="11" Padding="8,3" Margin="6,0,0,0"
+                            IsVisible="{Binding $parent[ItemsControl].((vm:StudentPerformanceOverviewViewModel)DataContext).IsTeacherMode}"/>
+                  </Grid>
+                </DataTemplate>
+              </ItemsControl.ItemTemplate>
+            </ItemsControl>
+            <TextBlock Text="Keine sonstigen Noten im gewählten Zeitraum." Classes="emptyhint"
+                       IsVisible="{Binding !OtherRows.Count}"/>
+          </StackPanel>
+
+          <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}" CornerRadius="8" Padding="14">
+            <StackPanel Spacing="2">
+              <TextBlock Text="ZEUGNISNOTE (BERECHNET)" FontSize="11" FontWeight="Bold" Opacity="0.5"/>
+              <TextBlock Text="{Binding CurrentReportGradeDisplay}" FontSize="18" FontWeight="SemiBold"/>
+            </StackPanel>
+          </Border>
+        </StackPanel>
+
+        <StackPanel Grid.Column="1" Spacing="16">
+          <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}" CornerRadius="8" Padding="14">
+            <StackPanel Spacing="8">
+              <TextBlock Text="ZIELNOTE: WAS BRAUCHE ICH NOCH?" FontSize="11" FontWeight="Bold" Opacity="0.5"/>
+              <StackPanel Orientation="Horizontal" Spacing="6">
+                <TextBlock Text="Ziel:" VerticalAlignment="Center"/>
+                <TextBox Text="{Binding TargetGradeText}" Width="70" PlaceholderText="z.B. 2"/>
+                <TextBlock Text="in" VerticalAlignment="Center"/>
+                <ComboBox ItemsSource="{Binding TargetBucketOptions}" SelectedItem="{Binding TargetBucketName}" MinWidth="110"/>
+              </StackPanel>
+              <TextBlock Text="{Binding TargetResultDisplay}" TextWrapping="Wrap" FontSize="13"/>
+            </StackPanel>
+          </Border>
+
+          <Border Background="{DynamicResource SystemControlBackgroundAltHighBrush}" CornerRadius="8" Padding="14">
+            <StackPanel Spacing="8">
+              <TextBlock Text="WAS-WÄRE-WENN" FontSize="11" FontWeight="Bold" Opacity="0.5"/>
+              <StackPanel Orientation="Horizontal" Spacing="6">
+                <TextBlock Text="Zusätzliche Klausurnote:" VerticalAlignment="Center" TextWrapping="Wrap"/>
+                <TextBox Text="{Binding WhatIfExamGradeText}" Width="70" PlaceholderText="z.B. 3"/>
+              </StackPanel>
+              <TextBlock Text="{Binding WhatIfResultDisplay}" TextWrapping="Wrap" FontSize="13"/>
+            </StackPanel>
+          </Border>
+        </StackPanel>
+      </Grid>
+    </ScrollViewer>
+
+    <Grid Grid.Row="3" ColumnDefinitions="*,Auto" Margin="0,16,0,0">
+      <Button Grid.Column="1" Content="Schließen" Click="OnClose"/>
+    </Grid>
+  </Grid>
+</Window>