An event card joins and leaves the event

PrivaPub lets a persona join another server's event (owner decision
2026-10-05). The card of a remote event shows the persona's participation
(pending, accepted, rejected) with Join or Leave, except for events by
invitation or taken on another site. Joining is public on the event's
server, so the first join asks the persona once, as reactions and votes do,
remembered apart from them (PublicAct).

The e2e joins the event SocialPub's Mobilizon scenario keeps, checks the
participant on Mobilizon and PrivaPub's answer, and leaves it.

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

Models/PublicActionNotices.cs

@@ -1,10 +1,19 @@
 namespace decePubClient.Models;
 
 /// <summary>
-/// The personas already told that their reactions and poll votes are public (owner decision, PrivaPub's ROADMAP: each
-/// persona is told once, before its first reaction or vote). Kept in localStorage under its type name.
+/// The personas already told that an act of theirs is public (owner decision, PrivaPub's ROADMAP: each persona is told
+/// once, before its first one): reactions and poll votes, and joining an event. Kept in localStorage under its type name.
 /// </summary>
 public class PublicActionNotices
 {
+	/// <summary>Told about reactions and poll votes.</summary>
 	public List<string> PersonaIds { get; set; } = [];
+	/// <summary>Told about joining events.</summary>
+	public List<string> EventPersonaIds { get; set; } = [];
+}
+
+public enum PublicAct
+{
+	Reaction = 0,
+	Participation = 1
 }