Mbin joins the pasture; a magazine's own threads and locks are taken

Mbin 1.10.1 runs in the pasture (its image, a messenger worker, a RabbitMQ
of its own, its API limits raised), and peers/mbin_token.py gets mbuser's
token through the authorization-code flow. scenarios/mbin.sh: 24 checks and
one known gap, magazines both ways, titled threads, a Note to a magazine as
a microblog post, comments, favourites and upvotes both ways, a moderator's
lock, unlock and removal, the unfollow and statistics.

What it showed:
- Mbin sends a magazine's threads to its subscribers as the author's Create,
  the magazine as its audience, never announced. A post whose group is
  followed here and lives on the post's own server is now kept as if
  announced; the same from another server is not.
- A moderator's lock is a bare Lock (and Undo{Lock}): LockHandler takes it
  from the post's own server only.
- Mbin takes private messages only as ChatMessage and its actors say
  nothing about it; PrivaPub never decides by a server's software, so this
  stays open as G-0008 for the owner.

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

PrivaPub/Middleware/SocialPubConfigurations.cs

@@ -93,6 +93,7 @@ namespace PrivaPub.Middleware
 				.AddSingleton<IActivityHandler, AnnounceHandler>()
 				.AddSingleton<IActivityHandler, FlagHandler>()
 				.AddSingleton<IActivityHandler, BlockHandler>()
+				.AddSingleton<IActivityHandler, LockHandler>()
 				.AddSingleton<IActivityHandler, CreateHandler>()
 				.AddSingleton<IActivityHandler, DeleteHandler>()
 				.AddSingleton<IActivityHandler, UpdateHandler>()