Put a cap on how many new messages we store browser-side. Unbounded growth is leading to crashed tabs and unresponsiveness.

git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@4638 ed5197a5-7fde-0310-b194-c3ffbd925b24

apps/ssb.json

@@ -1,5 +1,5 @@
 {
   "type": "tildefriends-app",
   "emoji": "🐌",
-  "previous": "&dc3Eovh35uB024L4dyFX+n8N37ove9STsKmkKlO/pcQ=.sha256"
+  "previous": "&vIYnoUkbz97WRvyunV+ETe+Y6tJk7tTEVvgYuwkoDiM=.sha256"
 }

apps/ssb/tf-app.js

@@ -156,6 +156,7 @@ class TfElement extends LitElement {
 			]);
 		if (messages && messages.length) {
 			this.unread = [...this.unread, ...messages];
+			this.unread = this.unread.slice(this.unread.length - 1024);
 		}
 	}