feat(notification-outbox): add Notification EF configuration and DbSet

src/ScadaLink.ConfigurationDatabase/Configurations/NotificationOutboxConfiguration.cs

@@ -0,0 +1,31 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using ScadaLink.Commons.Entities.Notifications;
+
+namespace ScadaLink.ConfigurationDatabase.Configurations;
+
+/// <summary>
+/// EF Core mapping for the central notification outbox entity. <see cref="Notification.TypeData"/>
+/// and <see cref="Notification.ResolvedTargets"/> are intentionally left unconstrained
+/// (nullable nvarchar(max)) as they carry variable-length JSON / target snapshots.
+/// </summary>
+public class NotificationOutboxConfiguration : IEntityTypeConfiguration<Notification>
+{
+    public void Configure(EntityTypeBuilder<Notification> builder)
+    {
+        builder.ToTable("Notifications");
+        builder.HasKey(n => n.NotificationId);
+        builder.Property(n => n.NotificationId).HasMaxLength(64);
+        builder.Property(n => n.Type).HasConversion<string>().HasMaxLength(32).IsRequired();
+        builder.Property(n => n.Status).HasConversion<string>().HasMaxLength(32).IsRequired();
+        builder.Property(n => n.ListName).HasMaxLength(200).IsRequired();
+        builder.Property(n => n.Subject).HasMaxLength(1000).IsRequired();
+        builder.Property(n => n.Body).IsRequired();
+        builder.Property(n => n.LastError).HasMaxLength(4000);
+        builder.Property(n => n.SourceSiteId).HasMaxLength(100).IsRequired();
+        builder.Property(n => n.SourceInstanceId).HasMaxLength(200);
+        builder.Property(n => n.SourceScript).HasMaxLength(200);
+        builder.HasIndex(n => new { n.Status, n.NextAttemptAt });
+        builder.HasIndex(n => new { n.SourceSiteId, n.CreatedAt });
+    }
+}

src/ScadaLink.ConfigurationDatabase/ScadaLinkDbContext.cs

@@ -69,6 +69,7 @@ public class ScadaLinkDbContext : DbContext, IDataProtectionKeyContext
     public DbSet<NotificationList> NotificationLists => Set<NotificationList>();
     public DbSet<NotificationRecipient> NotificationRecipients => Set<NotificationRecipient>();
     public DbSet<SmtpConfiguration> SmtpConfigurations => Set<SmtpConfiguration>();
+    public DbSet<Notification> Notifications => Set<Notification>();
 
     // Scripts
     public DbSet<SharedScript> SharedScripts => Set<SharedScript>();

tests/ScadaLink.ConfigurationDatabase.Tests/RepositoryCoverageTests.cs

@@ -243,6 +243,97 @@ public class NotificationRepositoryTests : IDisposable
     }
 }
 
+public class NotificationOutboxConfigurationTests : IDisposable
+{
+    private readonly ScadaLinkDbContext _context;
+
+    public NotificationOutboxConfigurationTests()
+    {
+        _context = SqliteTestHelper.CreateInMemoryContext();
+    }
+
+    public void Dispose()
+    {
+        _context.Database.CloseConnection();
+        _context.Dispose();
+    }
+
+    [Fact]
+    public async Task Notification_FullyPopulated_RoundTrips()
+    {
+        var id = Guid.NewGuid().ToString();
+        var siteEnqueuedAt = new DateTimeOffset(2026, 5, 19, 8, 0, 0, TimeSpan.Zero);
+        var createdAt = new DateTimeOffset(2026, 5, 19, 8, 0, 5, TimeSpan.Zero);
+        var lastAttemptAt = new DateTimeOffset(2026, 5, 19, 8, 1, 0, TimeSpan.Zero);
+        var nextAttemptAt = new DateTimeOffset(2026, 5, 19, 8, 2, 0, TimeSpan.Zero);
+        var deliveredAt = new DateTimeOffset(2026, 5, 19, 8, 3, 0, TimeSpan.Zero);
+
+        var notification = new Notification(id, NotificationType.Email, "Ops List",
+            "High Tank Level", "Tank 4 exceeded the high level threshold.", "site-north")
+        {
+            TypeData = "{\"channel\":\"email\"}",
+            Status = NotificationStatus.Retrying,
+            RetryCount = 3,
+            LastError = "SMTP timeout",
+            ResolvedTargets = "ops@example.test;duty@example.test",
+            SourceInstanceId = "instance-42",
+            SourceScript = "TankLevelAlarm",
+            SiteEnqueuedAt = siteEnqueuedAt,
+            CreatedAt = createdAt,
+            LastAttemptAt = lastAttemptAt,
+            NextAttemptAt = nextAttemptAt,
+            DeliveredAt = deliveredAt,
+        };
+
+        _context.Notifications.Add(notification);
+        await _context.SaveChangesAsync();
+        _context.ChangeTracker.Clear();
+
+        var loaded = await _context.Notifications.FindAsync(id);
+
+        Assert.NotNull(loaded);
+        Assert.Equal(id, loaded!.NotificationId);
+        Assert.Equal(NotificationType.Email, loaded.Type);
+        Assert.Equal(NotificationStatus.Retrying, loaded.Status);
+        Assert.Equal("Ops List", loaded.ListName);
+        Assert.Equal("High Tank Level", loaded.Subject);
+        Assert.Equal("Tank 4 exceeded the high level threshold.", loaded.Body);
+        Assert.Equal("{\"channel\":\"email\"}", loaded.TypeData);
+        Assert.Equal(3, loaded.RetryCount);
+        Assert.Equal("SMTP timeout", loaded.LastError);
+        Assert.Equal("ops@example.test;duty@example.test", loaded.ResolvedTargets);
+        Assert.Equal("site-north", loaded.SourceSiteId);
+        Assert.Equal("instance-42", loaded.SourceInstanceId);
+        Assert.Equal("TankLevelAlarm", loaded.SourceScript);
+        Assert.Equal(siteEnqueuedAt, loaded.SiteEnqueuedAt);
+        Assert.Equal(createdAt, loaded.CreatedAt);
+        Assert.Equal(lastAttemptAt, loaded.LastAttemptAt);
+        Assert.Equal(nextAttemptAt, loaded.NextAttemptAt);
+        Assert.Equal(deliveredAt, loaded.DeliveredAt);
+    }
+
+    [Fact]
+    public async Task Notification_StatusPersistsAsString()
+    {
+        var id = Guid.NewGuid().ToString();
+        var notification = new Notification(id, NotificationType.Email, "Ops List",
+            "Subject", "Body", "site-north")
+        {
+            Status = NotificationStatus.Parked,
+        };
+
+        _context.Notifications.Add(notification);
+        await _context.SaveChangesAsync();
+        _context.ChangeTracker.Clear();
+
+        var statusText = await _context.Database
+            .SqlQuery<string>($"SELECT Status AS Value FROM Notifications WHERE NotificationId = {id}")
+            .SingleAsync();
+
+        Assert.Equal("Parked", statusText);
+    }
+}
+
 public class SiteRepositoryTests : IDisposable
 {
     private readonly ScadaLinkDbContext _context;