Domain blocks: suspend, silence, reject media

DomainBlock (domain, severity, reject-media, public and private comment)
covers the domain and its subdomains. Admins manage them under
/clientapi/admin/domainblocks/{list,insert,delete}; the set is kept in
memory, reloaded on every change and at most five minutes stale.

A suspended domain is refused by FederationHttp.IsAllowed, so nothing is
fetched from it and no job delivers to it, and the inbox drops its
activities with a 202 before fetching any key. Reject-media strips the
attachments of posts from that domain. Silence is recorded for the
timelines and notifications that arrive in P1.2.

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

PrivaPub/Program.cs

@@ -154,6 +154,7 @@ try
 		var dbClient = app.Services.GetService(typeof(DbEntities)) as DbEntities;
 		var passwordHasher = app.Services.GetService(typeof(IPasswordHasher)) as IPasswordHasher;
 		await dbClient.Init(passwordHasher);
+		await app.Services.GetRequiredService<PrivaPub.Federation.Moderation.IDomainBlocks>().Reload(CancellationToken.None);
 	}
 	catch (Exception ex)
 	{