A notifications marker reads what it passes

Saving the notifications marker (/api/v1/markers) moved the marker but left
every notification unread, so a Mastodon client's unread count never fell.
The marker now marks read every notification up to it.

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

PrivaPub.Tests/Http/OneAnswerTests.cs

@@ -176,6 +176,11 @@ namespace PrivaPub.Tests.Http
 			Assert.True((await author.Client.Get("/api/v2/notifications/unread_count")).Ok().Body.Number("count") >= 1);
 			Assert.Equal(key, Assert.Single((await author.Client.Get($"/api/v2/notifications/{key}")).Ok().Body["notification_groups"]!.AsArray())!.Text("group_key"));
 			Assert.Equal(2, (await author.Client.Get($"/api/v2/notifications/{key}/accounts")).Ok().Array.Count);
+			// a notifications marker past them reads them
+			var newest = (await author.Client.Get("/api/v1/notifications")).Ok().Ids.First();
+			(await author.Client.Post("/api/v1/markers", ("notifications[last_read_id]", newest))).Ok();
+			Assert.Equal(0, (await author.Client.Get("/api/v2/notifications/unread_count")).Ok().Body.Number("count"));
+			Assert.Equal(0, (await author.Client.Get("/api/v1/notifications/unread_count")).Ok().Body.Number("count"));
 			Assert.Equal(HttpStatusCode.OK, (await author.Client.Post($"/api/v2/notifications/{key}/dismiss")).Status);
 			Assert.Equal(HttpStatusCode.NotFound, (await author.Client.Get($"/api/v2/notifications/{key}")).Status);
 		}

PrivaPub/Api/Mastodon/Controllers/TimelinesController.cs

@@ -146,6 +146,10 @@ namespace PrivaPub.Api.Mastodon.Controllers
 					.Option(o => o.IsUpsert = true)
 					.ExecuteAsync(token);
 				result[timeline] = new Entities.Marker { LastReadId = marker.LastReadId, Version = marker.Version, UpdatedAt = MastodonJson.Time(marker.UpdatedAt) };
+				// what the marker passes is read: the unread count (v1 and v2) counts only what is newer
+				if (timeline == "notifications")
+					await DB.Default.Update<NotificationEntity>().Match(n => n.AvatarId == MyId && !n.IsRead)
+						.Match(f => f.Lte(n => n.ID, lastRead)).Modify(n => n.IsRead, true).ExecuteAsync(token);
 			}
 			return Json(result);
 		}