Fix archive order (#382)

* Tiered reader returns events in wrong order, fixing it for 0.15

Author: alexeyzimarev

src/Core/src/Eventuous.Persistence/EventStore/TieredEventReader.cs

@@ -14,10 +14,10 @@ public async Task<StreamEvent[]> ReadEvents(StreamName streamName, StreamReadPos
         var hotEvents = await LoadStreamEvents(hotReader, start, count).NoContext();
 
         var archivedEvents = hotEvents.Length == 0 || hotEvents[0].Position > start.Value
-            ? await LoadStreamEvents(archiveReader, start, count - hotEvents.Length).NoContext()
+            ? await LoadStreamEvents(archiveReader, start, (int)hotEvents[0].Position).NoContext()
             : Enumerable.Empty<StreamEvent>();
 
-        return hotEvents.Concat(archivedEvents.Select(x => x with { FromArchive = true })).Distinct(Comparer).ToArray();
+        return archivedEvents.Select(x => x with { FromArchive = true }).Concat(hotEvents).Distinct(Comparer).ToArray();
 
         async Task<StreamEvent[]> LoadStreamEvents(IEventReader reader, StreamReadPosition startPosition, int localCount) {
             try {

src/Core/test/Eventuous.Tests.Persistence.Base/Store/TieredStoreTests.cs

@@ -23,8 +23,8 @@ protected async Task Should_load_hot_and_archive() {
         var actual = loaded.Select(x => (TestEventForTiers)x.Payload!).ToArray();
         actual.Should().BeEquivalentTo(testEvents);
 
-        loaded.Take(50).Select(x => x.FromArchive).Should().AllSatisfy(x => x.Should().BeFalse());
-        loaded.Skip(50).Select(x => x.FromArchive).Should().AllSatisfy(x => x.Should().BeTrue());
+        loaded.Take(50).Select(x => x.FromArchive).Should().AllSatisfy(x => x.Should().BeTrue());
+        loaded.Skip(50).Select(x => x.FromArchive).Should().AllSatisfy(x => x.Should().BeFalse());
     }
 
     readonly Fixture                      _fixture = new();