fix(store-and-forward): resolve StoreAndForward-003, re-triage 002 — fix retry-count off-by-one

src/ScadaLink.StoreAndForward/StoreAndForwardMessage.cs

@@ -20,10 +20,14 @@ public class StoreAndForwardMessage
     /// <summary>JSON-serialized payload containing the call details.</summary>
     public string PayloadJson { get; set; } = string.Empty;
 
-    /// <summary>Number of delivery attempts so far.</summary>
+    /// <summary>
+    /// Number of retry-sweep attempts performed so far. The initial (immediate or
+    /// caller-made) delivery attempt is attempt 0 and is not counted here; this
+    /// field counts only background retry attempts (StoreAndForward-003).
+    /// </summary>
     public int RetryCount { get; set; }
 
-    /// <summary>Maximum retry attempts before parking (0 = no limit).</summary>
+    /// <summary>Maximum retry-sweep attempts before parking (0 = no limit).</summary>
     public int MaxRetries { get; set; }
 
     /// <summary>Retry interval in milliseconds.</summary>