An id reused for another activity is not a copy

Friendica's activity ids are uniqid(): a short prefix and the microsecond. Two of its processes answering two follows at
once gave both Accepts one id, and PrivaPub, queueing each inbox activity once per id, dropped the second as a copy:
that follow stayed pending on our side while Friendica counted the persona as a follower (seen in the town's Friendica
pair). An id that comes back carrying another type, actor or object is now queued apart; a true copy is still dropped.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

PrivaPub.Tests/Support/Harness.cs

@@ -135,10 +135,12 @@ namespace PrivaPub.Tests.Support
 		public async Task<InboxResult> Deliver(RemoteActor sender, string path, JsonNode activity)
 		{
 			var result = await Receiver.Receive(sender.Post(Host, path, activity), default, CancellationToken.None);
+			// the job this delivery queued: under its id, or apart (a forwarded copy; an id its sender reused)
 			var id = activity is JsonObject ? activity["id"]?.GetValue<string>() : default;
 			var dedupe = (result.Reason == "forwarded" ? "inbox|forwarded|" : "inbox|") + id;
-			var job = await DB.Default.Find<Job>().Match(j => j.DedupeKey == dedupe).ExecuteFirstAsync();
-			if (job != default)
+			var job = await DB.Default.Find<Job>().Match(j => (j.DedupeKey == dedupe || j.DedupeKey.StartsWith(dedupe + "|")) && j.State == JobState.Pending)
+				.Sort(j => j.CreatedAt, Order.Descending).ExecuteFirstAsync();
+			if (job != default && result.Reason != "duplicate")
 				Assert.Equal(JobResult.Done, (await Processor.Handle(job, CancellationToken.None)).Result);
 			return result;
 		}