Relays: PrivaPub reads from the relays its configuration names

Federation:Relays names relays by their actor (or inbox) address; the instance actor follows Public at each, as Mastodon
subscribes, a minute after start and every six hours (asked again a day after no answer or a refusal, undone when a
relay is no longer named). What an accepted relay passes on comes to the federated timeline and nobody's home: a public
post it forwards (Activity-Relay), read again from its origin like any forwarded post, and a post it announces
(aode-relay), kept as its author's and never as the relay's boost. Nothing of a persona's is sent to a relay; sending
public posts there waits for the owner.

The pasture gains both relays (peers/relay.sh, peers/aoderelay.sh) and scenarios/relay.sh, 13 checks. The village
backlog is clean: 2574 checks pass, one known gap (Misskey's).

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

PrivaPub/Federation/Inbox/Arrival.cs

@@ -5,9 +5,10 @@ using PrivaPub.Models.Post;
 
 namespace PrivaPub.Federation.Inbox
 {
-	// Raw: the activity as it came, when its own author sent it (ReplyRelay passes it on as it is)
+	// Raw: the activity as it came, when its own author sent it (ReplyRelay passes it on as it is); ForwardedBy: the server
+	// that passed it on instead (a relay, a thread's server)
 	public sealed record Arrival(string ActivityId, string ActivityType, string ActorURI, string Inbox, string KeyId, string Algorithm,
-		IReadOnlyList<string> SignedHeaders, DateTime ReceivedAt, string Context = default, string Raw = default)
+		IReadOnlyList<string> SignedHeaders, DateTime ReceivedAt, string Context = default, string Raw = default, string ForwardedBy = default)
 	{
 		static readonly AsyncLocal<Arrival> current = new();