[CI] [SKIP TESTS] Add detailed Probe-Agent connection diagnostics

backend/tests/MoShiro.Backend.Tests/NodeRuntimeLogTests.cs

@@ -0,0 +1,27 @@
+using Fleet.Core;
+using MoShiro.Backend.Application;
+using MoShiro.Protocol;
+
+namespace MoShiro.Backend.Tests;
+
+public sealed class NodeRuntimeLogTests
+{
+    [Fact]
+    public void DiagnosticFieldsSurviveUpload_WhileSecretsAndOversizedFieldsRemainBounded()
+    {
+        var service = new NodeRuntimeLogService(TimeProvider.System);
+        var node = new NodeId("prb_diagnostics");
+        Dictionary<string, string> fields = Enumerable.Range(0, 18).ToDictionary(i => "field_" + i, _ => "value");
+        fields.Add("api_token", "must-not-survive");
+        fields.Add("detail", new string('x', 500));
+        fields.Add("overflow", "discard");
+        service.Append(node, [new NodeLogRecord(TimeProvider.System.GetUtcNow().ToUnixTimeMilliseconds(), "warn", "handshake failed", fields)], 0);
+
+        NodeRuntimeLog entry = Assert.Single(service.List(node, 10).Items);
+        Assert.Equal(20, entry.Fields.Count);
+        Assert.Equal("value", entry.Fields["field_17"]);
+        Assert.Equal("[redacted]", entry.Fields["api_token"]);
+        Assert.Equal(128, entry.Fields["detail"].Length);
+        Assert.False(entry.Fields.ContainsKey("overflow"));
+    }
+}