feat: add seating plans for learning groups

LehrerApp.Core/Interfaces/IRepositories.cs

@@ -19,6 +19,13 @@ public interface IGroupRepository
     void Save(LearningGroup group);
     void Delete(Guid id);
 }
+public interface ISeatingPlanRepository
+{
+    SeatingPlan? GetById(Guid id);
+    List<SeatingPlan> GetByGroup(Guid groupId);
+    void Save(SeatingPlan plan);
+    void Delete(Guid id);
+}
 public interface IGroupMembershipRepository
 {
     List<GroupMembership> GetByStudent(Guid studentId);

LehrerApp.Core/Models/SeatingPlan.cs

@@ -0,0 +1,25 @@
+namespace LehrerApp.Core.Models;
+
+/// <summary>
+/// Ein Sitzplan einer Lerngruppe. Eine Gruppe kann mehrere Pläne besitzen,
+/// beispielsweise für unterschiedliche Unterrichtsräume.
+/// </summary>
+public class SeatingPlan
+{
+    public Guid Id { get; set; } = Guid.NewGuid();
+    public Guid GroupId { get; set; }
+    public string Name { get; set; } = "";
+    public string Room { get; set; } = "";
+    public int Rows { get; set; } = 4;
+    public int Columns { get; set; } = 4;
+    public List<SeatAssignment> Assignments { get; set; } = [];
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+    public DateTime UpdatedAt { get; set; } = DateTime.UtcNow;
+}
+
+public class SeatAssignment
+{
+    public int Row { get; set; }
+    public int Column { get; set; }
+    public Guid StudentId { get; set; }
+}

LehrerApp.Core/Services/PersonalDataExportService.cs

@@ -21,7 +21,8 @@ public class PersonalDataExportService(
     IGradeRepository grades,
     IExamResultRepository examResults,
     IParticipationRepository participation,
-    IDocumentationRepository documentation)
+    IDocumentationRepository documentation,
+    ISeatingPlanRepository seatingPlans)
 {
     public string ExportAsJson(Guid studentId)
     {
@@ -43,6 +44,18 @@ public class PersonalDataExportService(
             Klausurergebnisse = examResults.GetByStudent(studentId),
             Mitarbeit = participation.GetByStudent(studentId),
             Dokumentation = documentation.GetByStudent(studentId),
+            Sitzplaetze = studentGroups
+                .SelectMany(g => seatingPlans.GetByGroup(g!.Id))
+                .SelectMany(plan => plan.Assignments
+                    .Where(a => a.StudentId == studentId)
+                    .Select(a => new
+                    {
+                        Sitzplan = plan.Name,
+                        plan.Room,
+                        Reihe = a.Row + 1,
+                        Platz = a.Column + 1,
+                    }))
+                .ToList(),
         };
 
         return JsonSerializer.Serialize(dto, new JsonSerializerOptions