feat(notif): NotificationDetailRequest query for full notification detail

src/ScadaLink.Commons/Messages/Notification/NotificationOutboxQueries.cs

@@ -76,6 +76,49 @@ public record DiscardNotificationResponse(
     bool Success,
     string? ErrorMessage);
 
+/// <summary>
+/// Outbox UI -> Central: request for the full detail of a single notification
+/// (including Body and resolved recipients), for the report detail modal.
+/// </summary>
+public record NotificationDetailRequest(
+    string CorrelationId,
+    string NotificationId);
+
+/// <summary>
+/// Central -> Outbox UI: full detail for one notification. On a repository fault or
+/// missing row, Success is false / Detail is null and ErrorMessage carries the cause.
+/// </summary>
+public record NotificationDetailResponse(
+    string CorrelationId,
+    bool Success,
+    string? ErrorMessage,
+    NotificationDetail? Detail);
+
+/// <summary>
+/// Full notification detail for the report detail modal — everything in the grid's
+/// NotificationSummary plus Body, ResolvedTargets (recipients), TypeData, SourceScript,
+/// and the additional lifecycle timestamps.
+/// </summary>
+public record NotificationDetail(
+    string NotificationId,
+    string Type,
+    string ListName,
+    string Subject,
+    string Body,
+    string Status,
+    int RetryCount,
+    string? LastError,
+    string? ResolvedTargets,
+    string? TypeData,
+    string SourceSiteId,
+    string? SourceInstanceId,
+    string? SourceScript,
+    DateTimeOffset SiteEnqueuedAt,
+    DateTimeOffset CreatedAt,
+    DateTimeOffset? LastAttemptAt,
+    DateTimeOffset? NextAttemptAt,
+    DateTimeOffset? DeliveredAt);
+
 /// <summary>
 /// Outbox UI -> Central: request for the notification outbox KPI summary.
 /// </summary>

src/ScadaLink.Communication/CommunicationService.cs

@@ -275,6 +275,13 @@ public class CommunicationService
             request, _options.QueryTimeout, cancellationToken);
     }
 
+    public async Task<NotificationDetailResponse> GetNotificationDetailAsync(
+        NotificationDetailRequest request, CancellationToken cancellationToken = default)
+    {
+        return await GetNotificationOutbox().Ask<NotificationDetailResponse>(
+            request, _options.QueryTimeout, cancellationToken);
+    }
+
     public async Task<NotificationKpiResponse> GetNotificationKpisAsync(
         NotificationKpiRequest request, CancellationToken cancellationToken = default)
     {

src/ScadaLink.NotificationOutbox/NotificationOutboxActor.cs

@@ -66,6 +66,7 @@ public class NotificationOutboxActor : ReceiveActor, IWithTimers
         Receive<InternalMessages.PurgeComplete>(_ => { });
         Receive<NotificationOutboxQueryRequest>(HandleQuery);
         Receive<NotificationStatusQuery>(HandleStatusQuery);
+        Receive<NotificationDetailRequest>(HandleDetailRequest);
         Receive<RetryNotificationRequest>(HandleRetry);
         Receive<DiscardNotificationRequest>(HandleDiscard);
         Receive<NotificationKpiRequest>(HandleKpiRequest);
@@ -674,6 +675,59 @@ public class NotificationOutboxActor : ReceiveActor, IWithTimers
             DeliveredAt: notification.DeliveredAt);
     }
 
+    /// <summary>
+    /// Handles a full-detail query for a single notification — backs the report detail
+    /// modal, which needs the Body and resolved recipients that the grid summary omits.
+    /// </summary>
+    private void HandleDetailRequest(NotificationDetailRequest request)
+    {
+        var sender = Sender;
+
+        DetailAsync(request).PipeTo(
+            sender,
+            success: response => response,
+            failure: ex => new NotificationDetailResponse(
+                request.CorrelationId, Success: false,
+                ErrorMessage: ex.GetBaseException().Message, Detail: null));
+    }
+
+    private async Task<NotificationDetailResponse> DetailAsync(NotificationDetailRequest request)
+    {
+        using var scope = _serviceProvider.CreateScope();
+        var repository = scope.ServiceProvider.GetRequiredService<INotificationOutboxRepository>();
+        var notification = await repository.GetByIdAsync(request.NotificationId);
+
+        if (notification is null)
+        {
+            return new NotificationDetailResponse(
+                request.CorrelationId, Success: false,
+                ErrorMessage: "notification not found", Detail: null);
+        }
+
+        var detail = new NotificationDetail(
+            notification.NotificationId,
+            notification.Type.ToString(),
+            notification.ListName,
+            notification.Subject,
+            notification.Body,
+            notification.Status.ToString(),
+            notification.RetryCount,
+            notification.LastError,
+            notification.ResolvedTargets,
+            notification.TypeData,
+            notification.SourceSiteId,
+            notification.SourceInstanceId,
+            notification.SourceScript,
+            notification.SiteEnqueuedAt,
+            notification.CreatedAt,
+            notification.LastAttemptAt,
+            notification.NextAttemptAt,
+            notification.DeliveredAt);
+
+        return new NotificationDetailResponse(
+            request.CorrelationId, Success: true, ErrorMessage: null, detail);
+    }
+
     /// <summary>
     /// Handles a manual retry request. Only a <c>Parked</c> notification can be retried;
     /// it is reset to <c>Pending</c> with a cleared retry count, next-attempt time, and