Add GuidelineId property to ZugferdInvoice model

Added a new `GuidelineId` property to the `ZugferdInvoice` model to store the ZUGFeRD Guideline ID extracted from XMP metadata. Updated the `AppDbContextModelSnapshot.cs` to reflect this change and created a migration (`20260527133241_AddGuidelineId`) to add the `GuidelineId` column to the `ZugferdInvoices` table.

Generated the corresponding designer file for the migration to define the updated database schema. Minor formatting changes were made to `ZugferdInvoice.cs` without functional impact.

DXApp.TemplateKitProject/Migrations/20260527133241_AddGuidelineId.Designer.cs

@@ -0,0 +1,85 @@
+// <auto-generated />
+using System;
+using DXApp.TemplateKitProject.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace DXApp.TemplateKitProject.Migrations
+{
+    [DbContext(typeof(AppDbContext))]
+    [Migration("20260527133241_AddGuidelineId")]
+    partial class AddGuidelineId
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "8.0.8")
+                .HasAnnotation("Relational:MaxIdentifierLength", 128);
+
+            SqlServerModelBuilderExtensions.UseIdentityColumns(modelBuilder);
+
+            modelBuilder.Entity("DXApp.TemplateKitProject.Models.ZugferdInvoice", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
+
+                    b.Property<string>("BuyerName")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("CurrencyCode")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("GuidelineId")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("Iban")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<DateTime>("ImportedAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<DateTime>("InvoiceDate")
+                        .HasColumnType("datetime2");
+
+                    b.Property<string>("InvoiceNumber")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("RawXml")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("ResultFilePath")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("SellerName")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("SellerTaxId")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("SourceType")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<decimal>("TaxAmount")
+                        .HasColumnType("decimal(18,2)");
+
+                    b.Property<decimal>("TotalAmount")
+                        .HasColumnType("decimal(18,2)");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("ZugferdInvoices");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

DXApp.TemplateKitProject/Migrations/20260527133241_AddGuidelineId.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace DXApp.TemplateKitProject.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddGuidelineId : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "GuidelineId",
+                table: "ZugferdInvoices",
+                type: "nvarchar(max)",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "GuidelineId",
+                table: "ZugferdInvoices");
+        }
+    }
+}

DXApp.TemplateKitProject/Migrations/AppDbContextModelSnapshot.cs

@@ -36,6 +36,9 @@ namespace DXApp.TemplateKitProject.Migrations
                     b.Property<string>("CurrencyCode")
                         .HasColumnType("nvarchar(max)");
 
+                    b.Property<string>("GuidelineId")
+                        .HasColumnType("nvarchar(max)");
+
                     b.Property<string>("Iban")
                         .HasColumnType("nvarchar(max)");
 

DXApp.TemplateKitProject/Models/ZugferdInvoice.cs

@@ -16,5 +16,6 @@
         public DateTime ImportedAt { get; set; }
         public string SourceType { get; set; } = string.Empty;      // "Upload" oder "Email"
         public string ResultFilePath { get; set; } = string.Empty;  // Pfad der Result-PDF
+        public string GuidelineId { get; set; } = string.Empty;     // ZUGFeRD Guideline-ID aus XMP
     }
 }