Notenschlüssel-Editor (1.3) und Einstellungen in Tabs strukturiert

- Notenschlüssel-Editor im ExamDialog: Stufen (Note/Prozentgrenze)
  bearbeitbar, Vorbelegung passend zum GradingSystem der Gruppe,
  Live-Anzeige der absoluten Punktegrenze je Stufe, Validierung
  (lückenlos, keine Dopplungen) über GradingService.ValidateGradingKey.
- Neues Modell GradingKeyTemplate + Repository: Notenschlüssel als
  Vorlage speichern/anwenden, direkt aus dem ExamDialog heraus.
- Einstellungen: Fächer / Kompetenzen / Notenschlüssel-Vorlagen sind
  jetzt eigene Tabs statt einer gemeinsam wachsenden Liste. Vorlagen
  zeigen nur noch eine kompakte Zeile; die Stufen-Bearbeitung läuft
  über ein Popup-Fenster (GradingKeyTemplateDialog).

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

LehrerApp.Core/Interfaces/IRepositories.cs

@@ -41,6 +41,14 @@ public interface IExamResultRepository
     void Save(ExamResult result);
     void SaveMany(List<ExamResult> results);
 }
+public interface IGradingKeyTemplateRepository
+{
+    List<GradingKeyTemplate> GetAll();
+    List<GradingKeyTemplate> GetByGradingSystem(GradingSystem system);
+    GradingKeyTemplate? GetById(Guid id);
+    void Save(GradingKeyTemplate template);
+    void Delete(Guid id);
+}
 public interface IGradeRepository
 {
     List<Grade> GetByStudentAndGroup(Guid studentId, Guid groupId);

LehrerApp.Core/Models/Exam.cs

@@ -29,6 +29,14 @@ public class GradingKeyEntry
     public string Grade { get; set; } = "";
     public double MinPercent { get; set; }
 }
+public class GradingKeyTemplate
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+    public string Name { get; set; } = "";
+    public GradingSystem GradingSystem { get; set; }
+    public List<GradingKeyEntry> Entries { get; set; } = [];
+    public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
+}
 public class ExamResult
 {
     public Guid Id { get; set; } = Guid.NewGuid();

LehrerApp.Core/Services/GradingService.cs

@@ -40,6 +40,21 @@ public class GradingService
         new() { Grade = "1",  MinPercent = 20.0 },
         new() { Grade = "0",  MinPercent = 0.0  },
     ];
+    public string? ValidateGradingKey(List<GradingKeyEntry> entries)
+    {
+        if (entries.Count < 2) return "Der Notenschlüssel braucht mindestens zwei Stufen.";
+        if (entries.Any(e => string.IsNullOrWhiteSpace(e.Grade)))
+            return "Jede Stufe braucht eine Bezeichnung.";
+        if (entries.Any(e => e.MinPercent < 0 || e.MinPercent > 100))
+            return "Prozentgrenzen müssen zwischen 0 und 100 liegen.";
+        var sorted = entries.OrderByDescending(e => e.MinPercent).ToList();
+        if (sorted.Select(e => e.MinPercent).Distinct().Count() != sorted.Count)
+            return "Prozentgrenzen dürfen sich nicht doppeln.";
+        if (sorted.Last().MinPercent != 0)
+            return "Die unterste Stufe muss bei 0 % liegen (lückenlose Abdeckung).";
+        return null;
+    }
+
     public double WeightedAverage(List<(string Grade, double Weight)> grades)
     {
         var numeric = grades

LehrerApp.Data/LiteDbContext.cs

@@ -26,6 +26,7 @@ public class LiteDbContext : IDisposable
     public ILiteCollection<Exam>          Exams         => _db.GetCollection<Exam>("exams");
     public ILiteCollection<ExamResult>    ExamResults   => _db.GetCollection<ExamResult>("exam_results");
     public ILiteCollection<Grade>         Grades        => _db.GetCollection<Grade>("grades");
+    public ILiteCollection<GradingKeyTemplate> GradingKeyTemplates => _db.GetCollection<GradingKeyTemplate>("grading_key_templates");
     public ILiteCollection<Unit>          Units         => _db.GetCollection<Unit>("units");
     public ILiteCollection<Lesson>        Lessons       => _db.GetCollection<Lesson>("lessons");
     public ILiteCollection<Documentation> Documentation => _db.GetCollection<Documentation>("documentation");
@@ -67,6 +68,7 @@ public class LiteDbContext : IDisposable
         ExamResults.EnsureIndex(x => x.StudentId);
         Grades.EnsureIndex(x => x.StudentId);
         Grades.EnsureIndex(x => x.GroupId);
+        GradingKeyTemplates.EnsureIndex(x => x.GradingSystem);
         Units.EnsureIndex(x => x.GroupId);
         Lessons.EnsureIndex(x => x.UnitId);
         Lessons.EnsureIndex(x => x.GroupId);

LehrerApp.Data/Repositories/AllRepositories.cs

@@ -114,6 +114,17 @@ public class ExamResultRepository(LiteDbContext db) : IExamResultRepository
     }
 }
 
+public class GradingKeyTemplateRepository(LiteDbContext db) : IGradingKeyTemplateRepository
+{
+    public List<GradingKeyTemplate> GetAll() =>
+        db.GradingKeyTemplates.FindAll().OrderBy(t => t.Name).ToList();
+    public List<GradingKeyTemplate> GetByGradingSystem(GradingSystem system) =>
+        db.GradingKeyTemplates.Find(t => t.GradingSystem == system).OrderBy(t => t.Name).ToList();
+    public GradingKeyTemplate? GetById(Guid id) => db.GradingKeyTemplates.FindById(id);
+    public void Save(GradingKeyTemplate t) { t.UpdatedAt = DateTime.UtcNow; db.GradingKeyTemplates.Upsert(t); }
+    public void Delete(Guid id) => db.GradingKeyTemplates.Delete(id);
+}
+
 public class GradeRepository(LiteDbContext db) : IGradeRepository
 {
     public List<Grade> GetByStudentAndGroup(Guid sid, Guid gid) =>

LehrerApp.Desktop/AppBootstrapper.cs

@@ -48,6 +48,7 @@ public static class AppBootstrapper
         services.AddSingleton<IExamRepository,          ExamRepository>();
         services.AddSingleton<IExamResultRepository,    ExamResultRepository>();
         services.AddSingleton<IGradeRepository,         GradeRepository>();
+        services.AddSingleton<IGradingKeyTemplateRepository, GradingKeyTemplateRepository>();
         services.AddSingleton<IUnitRepository,          UnitRepository>();
         services.AddSingleton<ILessonRepository,        LessonRepository>();
         services.AddSingleton<IDocumentationRepository, DocumentationRepository>();

LehrerApp.Desktop/ViewModels/Groups/ExamViewModels.cs

@@ -14,11 +14,13 @@ public partial class ExamDialogViewModel : ObservableObject
 {
     private readonly IExamRepository _exams;
     private readonly ICompetencyDomainRepository _competencyDomains;
+    private readonly IGradingKeyTemplateRepository _gradingKeyTemplates;
+    private readonly GradingService _grading;
     private readonly Guid _groupId;
     private readonly Guid? _subjectId;
     private readonly int _gradeLevel;
+    private readonly GradingSystem _gradingSystem;
     private readonly Exam? _editingExam;
-    private readonly List<GradingKeyEntry> _gradingKey;
     private readonly string _subjectName;
 
     [ObservableProperty] private string _title = "";
@@ -30,12 +32,17 @@ public partial class ExamDialogViewModel : ObservableObject
     [ObservableProperty] private double _totalPoints;
     [ObservableProperty] private bool _hasCompetencyCatalog;
     [ObservableProperty] private bool _useWeighting;
+    [ObservableProperty] private GradingKeyTemplate? _selectedTemplate;
+    [ObservableProperty] private string _newTemplateName = "";
+    [ObservableProperty] private string _gradingKeyValidation = "";
 
     public bool TotalPointsWarning => TotalPoints <= 0;
     public string TotalPointsDisplay =>
         $"{TotalPoints.ToString("0.##", CultureInfo.InvariantCulture)} Punkte gesamt";
 
     public ObservableCollection<ExamTaskEditItem> Tasks { get; } = [];
+    public ObservableCollection<GradingKeyEntryEditItem> GradingKeyEntries { get; } = [];
+    public ObservableCollection<GradingKeyTemplate> AvailableTemplates { get; } = [];
 
     public Exam? Result { get; private set; }
     public string DialogTitle => _editingExam is null ? "Neue Klausur anlegen" : "Klausur bearbeiten";
@@ -46,17 +53,23 @@ public partial class ExamDialogViewModel : ObservableObject
         ? "Kein Fach hinterlegt (siehe Lerngruppe)" : $"Fach: {_subjectName}";
 
     public ExamDialogViewModel(IExamRepository exams, ICompetencyDomainRepository competencyDomains,
+        IGradingKeyTemplateRepository gradingKeyTemplates, GradingService grading,
         Guid groupId, Guid? subjectId, int gradeLevel, GradingSystem gradingSystem,
         string defaultSubjectName, Exam? editingExam, Exam? duplicateSource)
     {
         _exams = exams; _competencyDomains = competencyDomains;
+        _gradingKeyTemplates = gradingKeyTemplates; _grading = grading;
         _groupId = groupId; _subjectId = subjectId; _gradeLevel = gradeLevel;
+        _gradingSystem = gradingSystem;
         _editingExam = editingExam;
         _subjectName = defaultSubjectName;
 
         HasCompetencyCatalog = subjectId.HasValue
             && _competencyDomains.GetBySubjectAndGrade(subjectId.Value, gradeLevel).Count > 0;
 
+        foreach (var t in _gradingKeyTemplates.GetByGradingSystem(gradingSystem))
+            AvailableTemplates.Add(t);
+
         var source = editingExam ?? duplicateSource;
         if (source is not null)
         {
@@ -68,16 +81,18 @@ public partial class ExamDialogViewModel : ObservableObject
             ExamNumber = source.ExamNumber;
             Notes      = source.Notes ?? "";
             ReturnedAtText = isDuplicate ? "" : source.ReturnedAt?.ToString("dd.MM.yyyy") ?? "";
-            _gradingKey = source.GradingKey
-                .Select(k => new GradingKeyEntry { Grade = k.Grade, MinPercent = k.MinPercent }).ToList();
             foreach (var t in source.Tasks.OrderBy(t => t.Nr))
                 AddTaskInternal(t.Title, t.MaxPoints, t.Weight, [.. t.CompetencyCodes]);
             UseWeighting = Tasks.Any(t => Math.Abs(t.Weight - 1.0) > 0.0001);
+            foreach (var e in source.GradingKey.OrderByDescending(e => e.MinPercent))
+                AddGradingKeyRowInternal(e.Grade, e.MinPercent);
         }
         else
         {
-            _gradingKey = gradingSystem == GradingSystem.Grades1To6
+            var defaults = gradingSystem == GradingSystem.Grades1To6
                 ? GradingService.DefaultKey1To6() : GradingService.DefaultKey0To15();
+            foreach (var e in defaults)
+                AddGradingKeyRowInternal(e.Grade, e.MinPercent);
         }
         foreach (var t in Tasks) t.ShowWeight = UseWeighting;
         RecomputeTotals();
@@ -158,8 +173,86 @@ public partial class ExamDialogViewModel : ObservableObject
         TotalPoints = Tasks.Sum(t => t.MaxPoints);
         OnPropertyChanged(nameof(TotalPointsWarning));
         OnPropertyChanged(nameof(TotalPointsDisplay));
+        RecomputeGradingKeyAbsolutes();
     }
 
+    // ── Notenschlüssel (1.3) ──────────────────────────────────────────────────
+
+    private void RecomputeGradingKeyAbsolutes()
+    {
+        foreach (var e in GradingKeyEntries)
+            e.AbsolutePointsDisplay = TotalPoints <= 0
+                ? "–"
+                : $"ab {(e.MinPercent / 100.0 * TotalPoints).ToString("0.##", CultureInfo.InvariantCulture)} " +
+                  $"von {TotalPoints.ToString("0.##", CultureInfo.InvariantCulture)} Punkten";
+    }
+
+    [RelayCommand]
+    private void AddGradingKeyRow()
+    {
+        AddGradingKeyRowInternal("", 0);
+        RecomputeGradingKeyAbsolutes();
+    }
+
+    private void AddGradingKeyRowInternal(string grade, double minPercent)
+    {
+        var item = new GradingKeyEntryEditItem
+        {
+            Grade = grade,
+            MinPercent = minPercent,
+            OnChanged = RecomputeGradingKeyAbsolutes,
+            OnRemove = RemoveGradingKeyRow,
+        };
+        GradingKeyEntries.Add(item);
+    }
+
+    private void RemoveGradingKeyRow(GradingKeyEntryEditItem item)
+    {
+        GradingKeyEntries.Remove(item);
+        RecomputeGradingKeyAbsolutes();
+    }
+
+    [RelayCommand(CanExecute = nameof(HasSelectedTemplate))]
+    private void ApplyTemplate()
+    {
+        if (SelectedTemplate is null) return;
+        GradingKeyEntries.Clear();
+        foreach (var e in SelectedTemplate.Entries.OrderByDescending(x => x.MinPercent))
+            AddGradingKeyRowInternal(e.Grade, e.MinPercent);
+        RecomputeGradingKeyAbsolutes();
+        GradingKeyValidation = "";
+    }
+
+    private bool HasSelectedTemplate() => SelectedTemplate is not null;
+
+    partial void OnSelectedTemplateChanged(GradingKeyTemplate? value) => ApplyTemplateCommand.NotifyCanExecuteChanged();
+
+    [RelayCommand]
+    private void SaveAsTemplate()
+    {
+        if (string.IsNullOrWhiteSpace(NewTemplateName)) { GradingKeyValidation = "Vorlagenname erforderlich."; return; }
+
+        var entries = BuildGradingKeyEntries();
+        var error = _grading.ValidateGradingKey(entries);
+        if (error is not null) { GradingKeyValidation = error; return; }
+
+        var template = new GradingKeyTemplate
+        {
+            Name = NewTemplateName.Trim(),
+            GradingSystem = _gradingSystem,
+            Entries = entries,
+        };
+        _gradingKeyTemplates.Save(template);
+        AvailableTemplates.Add(template);
+        NewTemplateName = "";
+        GradingKeyValidation = "";
+    }
+
+    private List<GradingKeyEntry> BuildGradingKeyEntries() => GradingKeyEntries
+        .Select(e => new GradingKeyEntry { Grade = e.Grade.Trim(), MinPercent = e.MinPercent })
+        .OrderByDescending(e => e.MinPercent)
+        .ToList();
+
     [RelayCommand]
     private void Save()
     {
@@ -180,6 +273,11 @@ public partial class ExamDialogViewModel : ObservableObject
             returnedAt = r;
         }
 
+        var gradingKey = BuildGradingKeyEntries();
+        var gradingKeyError = _grading.ValidateGradingKey(gradingKey);
+        if (gradingKeyError is not null) { GradingKeyValidation = gradingKeyError; return; }
+        GradingKeyValidation = "";
+
         Result = _editingExam ?? new Exam { GroupId = _groupId };
         Result.Title      = Title.Trim();
         Result.Date       = date;
@@ -188,11 +286,28 @@ public partial class ExamDialogViewModel : ObservableObject
         Result.Notes      = string.IsNullOrWhiteSpace(Notes) ? null : Notes.Trim();
         Result.ReturnedAt = returnedAt;
         Result.Tasks      = Tasks.Select(t => t.ToModel()).ToList();
-        Result.GradingKey = _gradingKey;
+        Result.GradingKey = gradingKey;
         _exams.Save(Result);
     }
 }
 
+// ── Zeile im Notenschlüssel-Editor (1.3) ──────────────────────────────────────
+
+public partial class GradingKeyEntryEditItem : ObservableObject
+{
+    [ObservableProperty] private string _grade = "";
+    [ObservableProperty] private double _minPercent;
+    [ObservableProperty] private string _absolutePointsDisplay = "";
+
+    public Action? OnChanged { get; set; }
+    public Action<GradingKeyEntryEditItem>? OnRemove { get; set; }
+
+    partial void OnMinPercentChanged(double value) => OnChanged?.Invoke();
+    partial void OnGradeChanged(string value) => OnChanged?.Invoke();
+
+    [RelayCommand] private void Remove() => OnRemove?.Invoke(this);
+}
+
 // ── Zeile im Aufgaben-Editor (1.2.1 / 1.2.2 / 1.2.4) ─────────────────────────
 
 public partial class ExamTaskEditItem : ObservableObject

LehrerApp.Desktop/ViewModels/Settings/SettingsViewModel.cs

@@ -2,6 +2,7 @@ using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using LehrerApp.Core.Interfaces;
 using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
 using System.Collections.ObjectModel;
 using System.Text.Json;
 using System.Text.Json.Serialization;
@@ -14,6 +15,8 @@ public partial class SettingsViewModel : ObservableObject
 {
     private readonly ISubjectRepository          _subjects;
     private readonly ICompetencyDomainRepository _domainRepo;
+    private readonly IGradingKeyTemplateRepository _gradingKeyTemplates;
+    private readonly GradingService _grading;
 
     // ── Fächer ────────────────────────────────────────────────────────────────
 
@@ -33,13 +36,65 @@ public partial class SettingsViewModel : ObservableObject
 
     public ObservableCollection<DomainEditItem> Domains { get; } = [];
 
+    // ── Notenschlüssel-Vorlagen (1.3.2) ──────────────────────────────────────
+
+    [ObservableProperty] private string _newTemplateName = "";
+    [ObservableProperty] private string _newTemplateGradingSystemName = "Noten 1–6";
+    [ObservableProperty] private string _templateValidationMessage = "";
+
+    public List<string> GradingSystemOptions { get; } = ["Noten 1–6", "Punkte 0–15"];
+    public ObservableCollection<GradingKeyTemplateEditItem> GradingKeyTemplateList { get; } = [];
+
     // ── Konstruktor ───────────────────────────────────────────────────────────
 
-    public SettingsViewModel(ISubjectRepository subjects, ICompetencyDomainRepository domainRepo)
+    public SettingsViewModel(ISubjectRepository subjects, ICompetencyDomainRepository domainRepo,
+        IGradingKeyTemplateRepository gradingKeyTemplates, GradingService grading)
     {
         _subjects   = subjects;
         _domainRepo = domainRepo;
+        _gradingKeyTemplates = gradingKeyTemplates;
+        _grading    = grading;
         LoadSubjects();
+        LoadGradingKeyTemplates();
+    }
+
+    // ── Notenschlüssel-Vorlagen: Laden / Hinzufügen / Löschen ────────────────
+
+    private void LoadGradingKeyTemplates()
+    {
+        GradingKeyTemplateList.Clear();
+        foreach (var t in _gradingKeyTemplates.GetAll())
+            GradingKeyTemplateList.Add(new GradingKeyTemplateEditItem(t, _gradingKeyTemplates, _grading));
+    }
+
+    [RelayCommand]
+    private void AddGradingKeyTemplate()
+    {
+        if (string.IsNullOrWhiteSpace(NewTemplateName)) { TemplateValidationMessage = "Vorlagenname erforderlich."; return; }
+
+        var system = NewTemplateGradingSystemName == "Punkte 0–15"
+            ? GradingSystem.Points0To15 : GradingSystem.Grades1To6;
+        var defaults = system == GradingSystem.Grades1To6
+            ? GradingService.DefaultKey1To6() : GradingService.DefaultKey0To15();
+
+        var template = new GradingKeyTemplate
+        {
+            Name = NewTemplateName.Trim(),
+            GradingSystem = system,
+            Entries = defaults.Select(e => new GradingKeyEntry { Grade = e.Grade, MinPercent = e.MinPercent }).ToList(),
+        };
+        _gradingKeyTemplates.Save(template);
+        GradingKeyTemplateList.Add(new GradingKeyTemplateEditItem(template, _gradingKeyTemplates, _grading));
+        NewTemplateName = "";
+        TemplateValidationMessage = "";
+    }
+
+    [RelayCommand]
+    private void DeleteGradingKeyTemplate(GradingKeyTemplateEditItem? item)
+    {
+        if (item is null) return;
+        _gradingKeyTemplates.Delete(item.Id);
+        GradingKeyTemplateList.Remove(item);
     }
 
     // ── Fächer: Laden / Hinzufügen / Löschen ─────────────────────────────────
@@ -253,6 +308,88 @@ public class CompetencyItemVm
     }
 }
 
+// ── GradingKeyTemplateEditItem (1.3.2) ─────────────────────────────────────────
+
+public partial class GradingKeyTemplateEditItem : ObservableObject
+{
+    private readonly GradingKeyTemplate _template;
+    private readonly IGradingKeyTemplateRepository _repo;
+    private readonly GradingService _grading;
+
+    public Guid   Id                 { get; }
+    public string Name               { get; }
+    public string GradingSystemLabel { get; }
+
+    [ObservableProperty] private string _newGrade = "";
+    [ObservableProperty] private double _newMinPercent;
+    [ObservableProperty] private string _validation = "";
+    [ObservableProperty] private string _completenessWarning = "";
+
+    public ObservableCollection<GradingKeyEntryVm> Entries { get; } = [];
+
+    public GradingKeyTemplateEditItem(GradingKeyTemplate template, IGradingKeyTemplateRepository repo,
+        GradingService grading)
+    {
+        _template = template; _repo = repo; _grading = grading;
+        Id   = template.Id;
+        Name = template.Name;
+        GradingSystemLabel = template.GradingSystem == GradingSystem.Grades1To6
+            ? "Noten 1–6" : "Punkte 0–15";
+
+        foreach (var e in template.Entries.OrderByDescending(e => e.MinPercent))
+            Entries.Add(new GradingKeyEntryVm(e, DeleteEntry));
+        RecomputeCompleteness();
+    }
+
+    [RelayCommand]
+    private void AddEntry()
+    {
+        if (string.IsNullOrWhiteSpace(NewGrade)) { Validation = "Bezeichnung erforderlich."; return; }
+        if (NewMinPercent is < 0 or > 100) { Validation = "Prozentgrenze muss zwischen 0 und 100 liegen."; return; }
+        if (_template.Entries.Any(e => Math.Abs(e.MinPercent - NewMinPercent) < 0.0001))
+        { Validation = "Diese Prozentgrenze existiert bereits."; return; }
+
+        var entry = new GradingKeyEntry { Grade = NewGrade.Trim(), MinPercent = NewMinPercent };
+        _template.Entries.Add(entry);
+        _template.Entries = _template.Entries.OrderByDescending(e => e.MinPercent).ToList();
+        _repo.Save(_template);
+
+        Entries.Clear();
+        foreach (var e in _template.Entries) Entries.Add(new GradingKeyEntryVm(e, DeleteEntry));
+        NewGrade = ""; NewMinPercent = 0; Validation = "";
+        RecomputeCompleteness();
+    }
+
+    private void DeleteEntry(GradingKeyEntryVm vm)
+    {
+        _template.Entries.RemoveAll(e => e.Grade == vm.Grade && Math.Abs(e.MinPercent - vm.MinPercent) < 0.0001);
+        _repo.Save(_template);
+        Entries.Remove(vm);
+        RecomputeCompleteness();
+    }
+
+    private void RecomputeCompleteness() =>
+        CompletenessWarning = _grading.ValidateGradingKey(_template.Entries) ?? "";
+}
+
+// ── GradingKeyEntryVm ─────────────────────────────────────────────────────────
+
+public class GradingKeyEntryVm
+{
+    public string Grade      { get; }
+    public double MinPercent { get; }
+    public string Display    { get; }
+    public IRelayCommand DeleteCommand { get; }
+
+    public GradingKeyEntryVm(GradingKeyEntry e, Action<GradingKeyEntryVm> onDelete)
+    {
+        Grade      = e.Grade;
+        MinPercent = e.MinPercent;
+        Display    = $"{Grade} — ab {MinPercent.ToString("0.##")} %";
+        DeleteCommand = new RelayCommand(() => onDelete(this));
+    }
+}
+
 // ── Hilfklassen ───────────────────────────────────────────────────────────────
 
 public class SubjectListItem(Subject s)

LehrerApp.Desktop/Views/Groups/ExamDialog.axaml

@@ -1,6 +1,7 @@
 <Window xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Groups"
+        xmlns:models="clr-namespace:LehrerApp.Core.Models;assembly=LehrerApp.Core"
         x:Class="LehrerApp.Desktop.Views.Groups.ExamDialog"
         x:DataType="vm:ExamDialogViewModel"
         Title="{Binding DialogTitle}"
@@ -112,6 +113,51 @@
 
         <TextBlock Text="{Binding ValidationMessage}" Foreground="Red" FontSize="12"
                    IsVisible="{Binding ValidationMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+
+        <Separator Margin="0,4"/>
+
+        <Grid ColumnDefinitions="*,Auto">
+          <TextBlock Grid.Column="0" Text="Notenschlüssel" FontSize="14" FontWeight="SemiBold" VerticalAlignment="Center"/>
+          <Button Grid.Column="1" Content="＋ Stufe" Command="{Binding AddGradingKeyRowCommand}"/>
+        </Grid>
+
+        <Grid ColumnDefinitions="*,8,Auto">
+          <ComboBox Grid.Column="0" ItemsSource="{Binding AvailableTemplates}"
+                    SelectedItem="{Binding SelectedTemplate}"
+                    PlaceholderText="Vorlage auswählen" HorizontalAlignment="Stretch">
+            <ComboBox.ItemTemplate>
+              <DataTemplate x:DataType="models:GradingKeyTemplate">
+                <TextBlock Text="{Binding Name}"/>
+              </DataTemplate>
+            </ComboBox.ItemTemplate>
+          </ComboBox>
+          <Button Grid.Column="2" Content="Anwenden" Command="{Binding ApplyTemplateCommand}"/>
+        </Grid>
+
+        <ItemsControl ItemsSource="{Binding GradingKeyEntries}">
+          <ItemsControl.ItemTemplate>
+            <DataTemplate x:DataType="vm:GradingKeyEntryEditItem">
+              <Grid ColumnDefinitions="90,90,*,Auto" Margin="0,0,0,6">
+                <TextBox Grid.Column="0" Text="{Binding Grade}" PlaceholderText="Note" Margin="0,0,6,0"/>
+                <NumericUpDown Grid.Column="1" Value="{Binding MinPercent}" Minimum="0" Maximum="100"
+                               FormatString="0.##" Width="90" ShowButtonSpinner="False" Margin="0,0,6,0"
+                               ToolTip.Tip="Mindest-Prozentgrenze"/>
+                <TextBlock Grid.Column="2" Text="{Binding AbsolutePointsDisplay}" FontSize="12" Opacity="0.65"
+                           VerticalAlignment="Center"/>
+                <Button Grid.Column="3" Content="✕" Command="{Binding RemoveCommand}" Padding="6,2"
+                        ToolTip.Tip="Entfernen"/>
+              </Grid>
+            </DataTemplate>
+          </ItemsControl.ItemTemplate>
+        </ItemsControl>
+
+        <TextBlock Text="{Binding GradingKeyValidation}" Foreground="Red" FontSize="12"
+                   IsVisible="{Binding GradingKeyValidation, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+
+        <Grid ColumnDefinitions="*,8,Auto">
+          <TextBox Grid.Column="0" Text="{Binding NewTemplateName}" PlaceholderText="Name für neue Vorlage"/>
+          <Button Grid.Column="2" Content="Als Vorlage speichern" Command="{Binding SaveAsTemplateCommand}"/>
+        </Grid>
       </StackPanel>
     </ScrollViewer>
 

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

@@ -1,6 +1,7 @@
 using Avalonia.Controls;
 using LehrerApp.Core.Interfaces;
 using LehrerApp.Core.Models;
+using LehrerApp.Core.Services;
 using LehrerApp.Desktop.ViewModels.Groups;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -56,6 +57,8 @@ public partial class GroupDetailView : UserControl
         var dialogVm = new ExamDialogViewModel(
             App.Services.GetRequiredService<IExamRepository>(),
             App.Services.GetRequiredService<ICompetencyDomainRepository>(),
+            App.Services.GetRequiredService<IGradingKeyTemplateRepository>(),
+            App.Services.GetRequiredService<GradingService>(),
             groupId, vm.Group.SubjectId, vm.Group.GradeLevel, vm.Group.GradingSystem,
             vm.Group.Subject ?? "", editingExam, duplicateSource);
 

LehrerApp.Desktop/Views/Settings/GradingKeyTemplateDialog.axaml

@@ -0,0 +1,46 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="clr-namespace:LehrerApp.Desktop.ViewModels.Settings"
+        x:Class="LehrerApp.Desktop.Views.Settings.GradingKeyTemplateDialog"
+        x:DataType="vm:GradingKeyTemplateEditItem"
+        Title="{Binding Name}"
+        Width="420" SizeToContent="Height" MinHeight="300"
+        CanResize="False" WindowStartupLocation="CenterOwner">
+
+  <Grid RowDefinitions="*,Auto" Margin="24">
+    <StackPanel Grid.Row="0" Spacing="10">
+      <StackPanel>
+        <TextBlock Text="{Binding Name}" FontSize="18" FontWeight="SemiBold"/>
+        <TextBlock Text="{Binding GradingSystemLabel}" FontSize="12" Opacity="0.5"/>
+      </StackPanel>
+
+      <TextBlock Text="{Binding CompletenessWarning}" Foreground="Red" FontSize="12" TextWrapping="Wrap"
+                 IsVisible="{Binding CompletenessWarning, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+
+      <ItemsControl ItemsSource="{Binding Entries}">
+        <ItemsControl.ItemTemplate>
+          <DataTemplate x:DataType="vm:GradingKeyEntryVm">
+            <Grid ColumnDefinitions="*,Auto" Margin="0,3">
+              <TextBlock Grid.Column="0" Text="{Binding Display}" VerticalAlignment="Center" FontSize="13"/>
+              <Button Grid.Column="1" Content="×" Padding="7,2" FontSize="13" Command="{Binding DeleteCommand}"/>
+            </Grid>
+          </DataTemplate>
+        </ItemsControl.ItemTemplate>
+      </ItemsControl>
+
+      <TextBlock Text="{Binding Validation}" Foreground="Red" FontSize="11"
+                 IsVisible="{Binding Validation, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+
+      <Grid ColumnDefinitions="*,8,90,8,Auto">
+        <TextBox Grid.Column="0" Text="{Binding NewGrade}"
+                 PlaceholderText="Note  (z.B. 2 oder 11)" FontSize="12"/>
+        <NumericUpDown Grid.Column="2" Value="{Binding NewMinPercent}" Minimum="0" Maximum="100"
+                       FormatString="0.##" ShowButtonSpinner="False" FontSize="12"
+                       ToolTip.Tip="Mindest-Prozentgrenze"/>
+        <Button Grid.Column="4" Content="＋" Command="{Binding AddEntryCommand}"/>
+      </Grid>
+    </StackPanel>
+
+    <Button Grid.Row="1" Content="Fertig" HorizontalAlignment="Stretch" Margin="0,20,0,0" Click="OnClose"/>
+  </Grid>
+</Window>

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

@@ -0,0 +1,11 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+
+namespace LehrerApp.Desktop.Views.Settings;
+
+public partial class GradingKeyTemplateDialog : Window
+{
+    public GradingKeyTemplateDialog() => InitializeComponent();
+
+    private void OnClose(object? sender, RoutedEventArgs e) => Close();
+}

LehrerApp.Desktop/Views/Settings/SettingsView.axaml

@@ -4,14 +4,17 @@
              x:Class="LehrerApp.Desktop.Views.Settings.SettingsView"
              x:DataType="vm:SettingsViewModel">
 
+  <Grid RowDefinitions="Auto,*">
+
+    <TextBlock Grid.Row="0" Text="Einstellungen" FontSize="22" FontWeight="SemiBold"
+               Margin="32,28,32,0"/>
+
+    <TabbedPage Grid.Row="1" TabPlacement="Top">
+
+      <!-- Tab: Fächer -->
+      <ContentPage Header="Fächer">
         <ScrollViewer>
-    <StackPanel Margin="32,28" Spacing="32" MaxWidth="640">
+          <StackPanel Margin="32,20,32,28" Spacing="14" MaxWidth="640">
-
-      <TextBlock Text="Einstellungen" FontSize="22" FontWeight="SemiBold"/>
-
-      <!-- ── FÄCHER ────────────────────────────────────────────────── -->
-      <StackPanel Spacing="10">
-        <TextBlock Text="FÄCHER" FontSize="10" FontWeight="Bold" Opacity="0.4"/>
 
             <ItemsControl ItemsSource="{Binding Subjects}">
               <ItemsControl.ItemTemplate>
@@ -48,11 +51,15 @@
                            IsVisible="{Binding ValidationMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
               </StackPanel>
             </Border>
-      </StackPanel>
 
-      <!-- ── KOMPETENZKATALOGE ─────────────────────────────────────── -->
+          </StackPanel>
-      <StackPanel Spacing="10">
+        </ScrollViewer>
-        <TextBlock Text="KOMPETENZKATALOGE" FontSize="10" FontWeight="Bold" Opacity="0.4"/>
+      </ContentPage>
+
+      <!-- Tab: Kompetenzen -->
+      <ContentPage Header="Kompetenzen">
+        <ScrollViewer>
+          <StackPanel Margin="32,20,32,28" Spacing="14" MaxWidth="640">
 
             <!-- Fach + Klassenstufe Auswahl + Import/Export -->
             <Grid ColumnDefinitions="*,12,120,12,Auto,8,Auto">
@@ -151,7 +158,70 @@
             </Border>
 
           </StackPanel>
+        </ScrollViewer>
+      </ContentPage>
+
+      <!-- Tab: Notenschlüssel-Vorlagen -->
+      <ContentPage Header="Notenschlüssel-Vorlagen">
+        <ScrollViewer>
+          <StackPanel Margin="32,20,32,28" Spacing="14" MaxWidth="640">
+
+            <TextBlock Text="Noch keine Vorlagen angelegt." Opacity="0.4" FontSize="13"
+                       IsVisible="{Binding !GradingKeyTemplateList.Count}"/>
+
+            <ItemsControl ItemsSource="{Binding GradingKeyTemplateList}">
+              <ItemsControl.ItemTemplate>
+                <DataTemplate DataType="vm:GradingKeyTemplateEditItem">
+                  <Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
+                          BorderThickness="0,0,0,1" Padding="0,9">
+                    <Grid ColumnDefinitions="*,Auto,Auto">
+                      <StackPanel Grid.Column="0">
+                        <TextBlock Text="{Binding Name}" FontWeight="SemiBold" FontSize="14"/>
+                        <TextBlock FontSize="12" Opacity="0.5">
+                          <Run Text="{Binding GradingSystemLabel}"/>
+                          <Run Text=" · "/>
+                          <Run Text="{Binding Entries.Count}"/>
+                          <Run Text=" Stufen"/>
+                        </TextBlock>
+                        <TextBlock Text="{Binding CompletenessWarning}" Foreground="Red" FontSize="11"
+                                   TextWrapping="Wrap"
+                                   IsVisible="{Binding CompletenessWarning, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+                      </StackPanel>
+                      <Button Grid.Column="1" Content="Bearbeiten" FontSize="12" Padding="10,4"
+                              Margin="8,0,0,0" Tag="{Binding}" Click="OnEditGradingKeyTemplateClick"/>
+                      <Button Grid.Column="2" Content="Löschen" FontSize="12" Padding="10,4"
+                              Margin="8,0,0,0"
+                              Command="{Binding $parent[ItemsControl].((vm:SettingsViewModel)DataContext).DeleteGradingKeyTemplateCommand}"
+                              CommandParameter="{Binding}"/>
+                    </Grid>
+                  </Border>
+                </DataTemplate>
+              </ItemsControl.ItemTemplate>
+            </ItemsControl>
+
+            <!-- Neue Vorlage anlegen -->
+            <Border BorderBrush="{DynamicResource SystemControlForegroundBaseLowBrush}"
+                    BorderThickness="1" CornerRadius="6" Padding="14,12">
+              <StackPanel Spacing="10">
+                <TextBlock Text="Neue Vorlage" FontSize="12" FontWeight="SemiBold" Opacity="0.7"/>
+                <Grid ColumnDefinitions="*,12,140,12,Auto">
+                  <TextBox Grid.Column="0" Text="{Binding NewTemplateName}"
+                           PlaceholderText="Vorlagenname  (z.B. Standard Oberstufe)"/>
+                  <ComboBox Grid.Column="2" ItemsSource="{Binding GradingSystemOptions}"
+                            SelectedItem="{Binding NewTemplateGradingSystemName}"
+                            HorizontalAlignment="Stretch"/>
+                  <Button  Grid.Column="4" Content="Anlegen"
+                           Command="{Binding AddGradingKeyTemplateCommand}"/>
+                </Grid>
+                <TextBlock Text="{Binding TemplateValidationMessage}" Foreground="Red" FontSize="12"
+                           IsVisible="{Binding TemplateValidationMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
+              </StackPanel>
+            </Border>
 
           </StackPanel>
         </ScrollViewer>
+      </ContentPage>
+
+    </TabbedPage>
+  </Grid>
 </UserControl>

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

@@ -42,4 +42,12 @@ public partial class SettingsView : UserControl
         var json = vm.ExportCatalog();
         await File.WriteAllTextAsync(file.Path.LocalPath, json);
     }
+
+    private async void OnEditGradingKeyTemplateClick(object? sender, RoutedEventArgs e)
+    {
+        if (sender is not Button { Tag: GradingKeyTemplateEditItem item }) return;
+        var dialog = new GradingKeyTemplateDialog { DataContext = item };
+        var owner = TopLevel.GetTopLevel(this) as Window;
+        if (owner is not null) await dialog.ShowDialog(owner);
+    }
 }

TODO.md

@@ -50,12 +50,14 @@ Modelle `Exam`, `ExamTask`, `GradingKeyEntry`, `ExamResult` existieren bereits i
       Voraussetzung für die Kompetenzauswertung in 8.3.
 
 ### 1.3 Notenschlüssel
-- [ ] **1.3.1** Editor für `GradingKey` mit Vorbelegung aus
+- [x] **1.3.1** Editor für `GradingKey` mit Vorbelegung aus
       `GradingService.DefaultKey1To6()` / `DefaultKey0To15()` je nach `GradingSystem` der Gruppe.
-- [ ] **1.3.2** Notenschlüssel als wiederverwendbare Vorlage speichern (neues Modell
+      Umgesetzt im `ExamDialog` (Teil von 1.1.1), analog zum Aufgaben-Editor.
+- [x] **1.3.2** Notenschlüssel als wiederverwendbare Vorlage speichern (neues Modell
       `GradingKeyTemplate` + Repository) und in Einstellungen verwalten.
-- [ ] **1.3.3** Live-Vorschau: Punktegrenzen absolut anzeigen (z.B. "Note 2 ab 45 von 60 P.").
+- [x] **1.3.3** Live-Vorschau: Punktegrenzen absolut anzeigen (z.B. "Note 2 ab 45 von 60 P.").
-- [ ] **1.3.4** Validierung: lückenlose, absteigende Prozentgrenzen, keine Dopplungen.
+- [x] **1.3.4** Validierung: lückenlose, absteigende Prozentgrenzen, keine Dopplungen
+      (`GradingService.ValidateGradingKey`).
 
 ### 1.4 Punkteeingabe & Korrektur
 - [ ] **1.4.1** Eingaberaster: Zeilen = Schüler, Spalten = Aufgaben, letzte Spalte Summe + Note.