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

tests/ScadaLink.StoreAndForward.Tests/StoreAndForwardServiceTests.cs

@@ -267,6 +267,60 @@ public class StoreAndForwardServiceTests : IAsyncLifetime, IDisposable
         Assert.Equal(0, msg.RetryCount);
     }
 
+    /// <summary>
+    /// StoreAndForward-017: the Retry activity-log entry must carry the parked
+    /// message's true category, not a hard-coded ExternalSystem.
+    /// </summary>
+    [Fact]
+    public async Task RetryParkedMessageAsync_ActivityUsesMessageRealCategory()
+    {
+        _service.RegisterDeliveryHandler(StoreAndForwardCategory.Notification,
+            _ => throw new HttpRequestException("fail"));
+
+        var result = await _service.EnqueueAsync(
+            StoreAndForwardCategory.Notification, "ops-list", """{}""",
+            maxRetries: 1);
+        await _service.RetryPendingMessagesAsync(); // -> parked
+
+        var categories = new List<StoreAndForwardCategory>();
+        _service.OnActivity += (action, category, _) =>
+        {
+            if (action == "Retry") categories.Add(category);
+        };
+
+        var retried = await _service.RetryParkedMessageAsync(result.MessageId);
+        Assert.True(retried);
+
+        Assert.Equal(new[] { StoreAndForwardCategory.Notification }, categories);
+    }
+
+    /// <summary>
+    /// StoreAndForward-017: the Discard activity-log entry must carry the parked
+    /// message's true category, not a hard-coded ExternalSystem.
+    /// </summary>
+    [Fact]
+    public async Task DiscardParkedMessageAsync_ActivityUsesMessageRealCategory()
+    {
+        _service.RegisterDeliveryHandler(StoreAndForwardCategory.CachedDbWrite,
+            _ => throw new HttpRequestException("fail"));
+
+        var result = await _service.EnqueueAsync(
+            StoreAndForwardCategory.CachedDbWrite, "site-db", """{}""",
+            maxRetries: 1);
+        await _service.RetryPendingMessagesAsync(); // -> parked
+
+        var categories = new List<StoreAndForwardCategory>();
+        _service.OnActivity += (action, category, _) =>
+        {
+            if (action == "Discard") categories.Add(category);
+        };
+
+        var discarded = await _service.DiscardParkedMessageAsync(result.MessageId);
+        Assert.True(discarded);
+
+        Assert.Equal(new[] { StoreAndForwardCategory.CachedDbWrite }, categories);
+    }
+
     [Fact]
     public async Task DiscardParkedMessageAsync_PermanentlyRemoves()
     {