feat(engine): add FinlyticEngine microservice with trade lifecycle, AI reasoning gate, composite scoring, and unit tests

FinlyticEngine.Tests/TestSupport/FakeEngineRpcClient.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using FinlyticEngine.Services.Mqtt;
+
+namespace FinlyticEngine.Tests.TestSupport;
+
+/// <summary>
+/// Fake for <see cref="IEngineRpcClient"/>. Records every published MQTT event so tests can assert on
+/// fire-and-forget notifications without a real broker (Rules.md §13: isolated, non-destructive tests only).
+/// </summary>
+public class FakeEngineRpcClient : IEngineRpcClient
+{
+    public List<(string Topic, object? Data)> PublishedMessages { get; } = new();
+
+    /// <inheritdoc />
+    public Task<TResponse?> SendRpcRequestAsync<TResponse, TRequest>(string channel, TRequest requestData, TimeSpan? timeout = null)
+        where TResponse : class
+        where TRequest : class
+        => throw new InvalidOperationException(
+            "SendRpcRequestAsync is only used by EvaluateAssetAsync, which is out of scope for the tenant-boundary tests in this suite.");
+
+    /// <inheritdoc />
+    public Task PublishAsync<T>(string topic, T data, bool retain = false)
+    {
+        PublishedMessages.Add((topic, data));
+        return Task.CompletedTask;
+    }
+}