chore: initialize standalone UPM package

Tools~/DotNet/ShrinkEventBus.Smoke/Program.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using ShrinkEventBus;
+
+internal readonly struct PingEvent : IShrinkEvent
+{
+    public PingEvent(int value) => Value = value;
+    public int Value { get; }
+}
+
+[ShrinkEventSubscriber]
+internal sealed partial class SmokeSubscriber
+{
+    public int Sum { get; private set; }
+    public int ThreadId { get; private set; }
+
+    [ShrinkSubscribe]
+    private void OnPing(PingEvent evt)
+    {
+        Sum += evt.Value;
+        ThreadId = Thread.CurrentThread.ManagedThreadId;
+    }
+}
+
+[ShrinkEventSubscriber(DefaultBus = "game")]
+internal static partial class StaticSmokeSubscriber
+{
+    public static int Sum { get; set; }
+
+    [ShrinkSubscribe]
+    private static void OnPing(PingEvent evt) => Sum += evt.Value;
+}
+
+internal static class Program
+{
+    private static async Task<int> Main()
+    {
+        using var host = new ShrinkEventBusHost();
+        var game = host.CreateBus(ShrinkBusKey.Game, ShrinkBusOptions.Inline());
+        var workerKey = new ShrinkBusKey("worker", "smoke");
+        var worker = host.CreateBus(workerKey, ShrinkBusOptions.DedicatedThread());
+        var gameSubscriber = new SmokeSubscriber();
+        var workerSubscriber = new SmokeSubscriber();
+        var callerThread = Thread.CurrentThread.ManagedThreadId;
+
+        using var gameBinding = host.Attach(gameSubscriber, ShrinkBusKey.Game);
+        using var workerBinding = host.Attach(workerSubscriber, workerKey);
+        game.Post(new PingEvent(2));
+        await worker.PostAsync(new PingEvent(3));
+
+        if (gameSubscriber.Sum != 2 || workerSubscriber.Sum != 3 || StaticSmokeSubscriber.Sum != 2 ||
+            workerSubscriber.ThreadId == callerThread)
+        {
+            Console.Error.WriteLine("FAIL");
+            return 1;
+        }
+
+        Console.WriteLine("PASS");
+        return 0;
+    }
+}