feat(sitecallaudit): central→site Retry/Discard relay for parked operations

src/ScadaLink.Communication/Actors/SiteCommunicationActor.cs

@@ -167,6 +167,33 @@ public class SiteCommunicationActor : ReceiveActor, IWithTimers
             }
         });
 
+        // Task 5 (#22): central→site Retry/Discard relay for parked cached
+        // operations. SiteCallAuditActor relays these over the command/control
+        // channel; the parked-message handler executes them against the local
+        // S&F buffer and replies a ParkedOperationActionAck that routes back to
+        // the relaying SiteCallAuditActor's Ask.
+        Receive<RetryParkedOperation>(msg =>
+        {
+            if (_parkedMessageHandler != null)
+                _parkedMessageHandler.Forward(msg);
+            else
+            {
+                Sender.Tell(new ParkedOperationActionAck(
+                    msg.CorrelationId, Applied: false, "Parked message handler not available"));
+            }
+        });
+
+        Receive<DiscardParkedOperation>(msg =>
+        {
+            if (_parkedMessageHandler != null)
+                _parkedMessageHandler.Forward(msg);
+            else
+            {
+                Sender.Tell(new ParkedOperationActionAck(
+                    msg.CorrelationId, Applied: false, "Parked message handler not available"));
+            }
+        });
+
         // Notification Outbox: forward a buffered notification submitted by the site
         // Store-and-Forward Engine to the central cluster. The original Sender (the
         // S&F forwarder's Ask) is forwarded as the ClusterClient.Send sender so the

src/ScadaLink.Communication/CommunicationService.cs

@@ -347,6 +347,33 @@ public class CommunicationService
         return await GetSiteCallAudit().Ask<PerSiteSiteCallKpiResponse>(
             request, _options.QueryTimeout, cancellationToken);
     }
+
+    /// <summary>
+    /// Task 5 (#22): relays an operator Retry of a parked cached call to its
+    /// owning site. The <c>SiteCallAuditActor</c> is Asked directly (it is
+    /// central-local); it in turn relays a <c>RetryParkedOperation</c> to the
+    /// owning site and replies a <see cref="RetrySiteCallResponse"/> carrying a
+    /// distinct site-unreachable outcome. Central never mutates the central
+    /// <c>SiteCalls</c> mirror row.
+    /// </summary>
+    public async Task<RetrySiteCallResponse> RetrySiteCallAsync(
+        RetrySiteCallRequest request, CancellationToken cancellationToken = default)
+    {
+        return await GetSiteCallAudit().Ask<RetrySiteCallResponse>(
+            request, _options.QueryTimeout, cancellationToken);
+    }
+
+    /// <summary>
+    /// Task 5 (#22): relays an operator Discard of a parked cached call to its
+    /// owning site. See <see cref="RetrySiteCallAsync"/> for the routing and
+    /// source-of-truth rationale.
+    /// </summary>
+    public async Task<DiscardSiteCallResponse> DiscardSiteCallAsync(
+        DiscardSiteCallRequest request, CancellationToken cancellationToken = default)
+    {
+        return await GetSiteCallAudit().Ask<DiscardSiteCallResponse>(
+            request, _options.QueryTimeout, cancellationToken);
+    }
 }
 
 /// <summary>