fix(store-and-forward): resolve StoreAndForward-015..017 — document maxRetries=0 contract, replicate operator retry/discard, real category in activity log

src/ScadaLink.StoreAndForward/ReplicationService.cs

@@ -73,6 +73,22 @@ public class ReplicationService
             message));
     }
 
+    /// <summary>
+    /// WP-11 / StoreAndForward-016: Replicates an operator-initiated requeue (a parked
+    /// message moved back to the pending queue) to standby (fire-and-forget). The
+    /// carried message reflects the active node's post-requeue state (Pending,
+    /// retry_count = 0) so the standby's copy can be brought into sync.
+    /// </summary>
+    public void ReplicateRequeue(StoreAndForwardMessage message)
+    {
+        if (!_options.ReplicationEnabled || _replicationHandler == null) return;
+
+        FireAndForget(new ReplicationOperation(
+            ReplicationOperationType.Requeue,
+            message.Id,
+            message));
+    }
+
     /// <summary>
     /// WP-11: Applies a replicated operation received from the active node.
     /// Used by the standby node to keep its SQLite in sync.
@@ -95,6 +111,15 @@ public class ReplicationService
                 operation.Message.Status = StoreAndForwardMessageStatus.Parked;
                 await storage.UpdateMessageAsync(operation.Message);
                 break;
+
+            case ReplicationOperationType.Requeue when operation.Message != null:
+                // StoreAndForward-016: an operator retried a parked message on the
+                // active node; mirror that on the standby by moving its row back to
+                // Pending with retry_count = 0 so a failover preserves the retry.
+                operation.Message.Status = StoreAndForwardMessageStatus.Pending;
+                operation.Message.RetryCount = 0;
+                await storage.UpdateMessageAsync(operation.Message);
+                break;
         }
     }
 
@@ -132,5 +157,10 @@ public enum ReplicationOperationType
 {
     Add,
     Remove,
-    Park
+    Park,
+    /// <summary>
+    /// StoreAndForward-016: an operator moved a parked message back to the pending
+    /// queue. The standby resets its matching row to Pending with retry_count = 0.
+    /// </summary>
+    Requeue
 }