test(contracts): round-trip provider status + degraded provenance

src/ZB.MOM.WW.MxGateway.Tests/Contracts/ProtobufContractRoundTripTests.cs

@@ -1332,6 +1332,56 @@ public sealed class ProtobufContractRoundTripTests
         Assert.Equal(kind, parsed.Kind);
     }
 
+    /// <summary>
+    ///     Verifies that an <see cref="AlarmFeedMessage"/> carrying the
+    ///     <c>provider_status</c> payload case round-trips and resolves to
+    ///     <see cref="AlarmFeedMessage.PayloadOneofCase.ProviderStatus"/>.
+    /// </summary>
+    [Fact]
+    public void Feed_RoundTripsProviderStatus()
+    {
+        var since = Timestamp.FromDateTime(new DateTime(2026, 6, 13, 9, 0, 0, DateTimeKind.Utc));
+        var original = new AlarmFeedMessage
+        {
+            ProviderStatus = new AlarmProviderStatus
+            {
+                Mode = AlarmProviderMode.Subtag,
+                Degraded = true,
+                Reason = "wnwrap poll failed 3x (HRESULT 0x80004005)",
+                Since = since,
+            },
+        };
+
+        var parsed = AlarmFeedMessage.Parser.ParseFrom(original.ToByteArray());
+
+        Assert.Equal(original, parsed);
+        Assert.Equal(AlarmFeedMessage.PayloadOneofCase.ProviderStatus, parsed.PayloadCase);
+        Assert.True(parsed.ProviderStatus.Degraded);
+        Assert.Equal(AlarmProviderMode.Subtag, parsed.ProviderStatus.Mode);
+    }
+
+    /// <summary>
+    ///     Verifies that an <see cref="OnAlarmTransitionEvent"/> carrying the
+    ///     new <c>degraded</c> and <c>source_provider</c> provenance fields
+    ///     round-trips with their values preserved.
+    /// </summary>
+    [Fact]
+    public void Transition_RoundTripsDegradedProvenance()
+    {
+        var t = new OnAlarmTransitionEvent
+        {
+            AlarmFullReference = "Galaxy!Area.Tank01.Level.HiHi",
+            TransitionKind = AlarmTransitionKind.Raise,
+            Degraded = true,
+            SourceProvider = AlarmProviderMode.Subtag,
+        };
+
+        var parsed = OnAlarmTransitionEvent.Parser.ParseFrom(t.ToByteArray());
+
+        Assert.True(parsed.Degraded);
+        Assert.Equal(AlarmProviderMode.Subtag, parsed.SourceProvider);
+    }
+
     /// <summary>
     ///     Verifies that an <see cref="MxCommandReply"/> with kind
     ///     <see cref="MxCommandKind.ReadBulk"/> and a populated