Notifications in groups, and what is unread

The Notifications tab reads grouped notifications (/api/v2/notifications):
likes and boosts of one post, or follows of one hour, are one card naming
both accounts of a pair, or the newest and how many others, with their
avatars. A notification the stream tells joins its group and waits on top.
The tab's badge counts what is unread; opening the tab moves the
notifications marker to the newest shown, which reads it on PrivaPub.

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

Components/Feed/FeedTabs.razor

@@ -14,6 +14,10 @@
 						<Header>
 							<i class="@type.GetTimelineTypeIcon()" aria-hidden="true"></i>
 							<span class="@(type == Filter.TimelineType ? null : "hidden xl:inline")">@TabName(type)</span>
+							@if (type is TimelineType.Notifications && UnreadNotifications > 0)
+							{
+								<DBadge Size="DSize.Xs" Color="DColor.Primary" title="@Localizer["{0} unread", UnreadNotifications]" data-unread>@UnreadNotifications</DBadge>
+							}
 						</Header>
 					</DTab>
 				}
@@ -92,6 +96,8 @@
 	[Parameter, EditorRequired] public FeedFilter Filter { get; set; }
 	[Parameter] public List<ViewGroup> Groups { get; set; } = [];
 	[Parameter] public List<MastodonList> Lists { get; set; } = [];
+	/// <summary>Groups of notifications newer than the persona's marker; a badge on the Notifications tab.</summary>
+	[Parameter] public int UnreadNotifications { get; set; }
 	[Parameter] public IEnumerable<NerdRow> Stats { get; set; } = [];
 	[Parameter] public bool IsComposing { get; set; }
 	[Parameter] public EventCallback OnCompose { get; set; }