A remote delete clears what it touched

Deleting a remote post now removes its timeline entries and the reblogs
of it and lowers its parent's reply count; deleting a remote actor also
drops the follows pointing at it and its entries in home timelines.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

PrivaPub.Tests/Domain/TimelineTests.cs

@@ -122,6 +122,26 @@ namespace PrivaPub.Tests.Domain
 			Assert.DoesNotContain("<p>parent</p>", (await Home(bobRoot, bob.Id)).Select(p => p.ContentHtml));
 		}
 
+		[Fact]
+		public async Task A_remote_delete_takes_the_post_out_of_home()
+		{
+			var (bobRoot, bob) = await _harness.Persona("bob");
+			var carol = new RemoteActor(_harness.Peer, "carol");
+			await Accepted(bobRoot, bob.Id, carol);
+			var create = Create(carol, text: "soon gone");
+			await _harness.Deliver(carol, "/human-centipede", create);
+			Assert.Single(await Home(bobRoot, bob.Id));
+
+			await _harness.Deliver(carol, "/human-centipede", new JsonObject
+			{
+				["id"] = $"{new Uri(carol.Id).GetLeftPart(UriPartial.Authority)}/deletes/{Guid.NewGuid():N}", ["type"] = "Delete", ["actor"] = carol.Id,
+				["object"] = new JsonObject { ["id"] = create["object"]!["id"]!.GetValue<string>(), ["type"] = "Tombstone" }
+			});
+
+			Assert.Empty(await Home(bobRoot, bob.Id));
+			Assert.False(await DB.Default.Find<TimelineEntry>().Match(e => e.AvatarId == bob.Id).ExecuteAnyAsync(TestContext.Current.CancellationToken));
+		}
+
 		[Fact]
 		public async Task A_mention_notifies_the_persona()
 		{