R6 moderation: roles, silence and suspension, bans that write nothing on the personas, deletions, report actions

Roles (user, moderator, administrator) from the CLI and /clientapi/admin/roots/{id}/role, never one's own nor the last
administrator. Silence keeps an account's posts out of public timelines, hashtags, trends, search and relays while its
followers still get them; suspension refuses and revokes a local persona's tokens, answers 404 for its posts and
collections, holds back every delivery and tells other servers nothing new, its actor unchanged; a suspended remote
account's activities are dropped and nothing goes to its own inbox (a shared one still serves its server). A banned
login's personas are held back in memory alone (Restrictions), so nothing pairs them in stored data. Personas and groups
are deleted one at a time (PersonaRemoval, GroupRemoval), by their login or an administrator with the password. Reports
resolve with an action and a note; posts are taken down, a remote copy hidden. Warnings reach the persona as Mastodon's
moderation_warning. Every staff act goes to the staff's log. Migration _020 limits posts from servers already silenced;
a restore keeps the moderation made since the backup.

Verified: interop.sh moderation gts mastodon with SecureMode, 194 passed; restore.sh, 25 passed, now with a suspension,
a silence and a takedown made after the backup.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WpVCoDeM1qUTRp4fXQdfof

FEDERATION.md

@@ -380,6 +380,31 @@ persona's public post outside any group, its edit and its deletion also go to th
 only with an LD signature or an FEP-8b32 proof: PrivaPub's carry a proof, so they reach Mastodon through both kinds of
 relay (checked live).
 
+## Moderation
+
+What this server's staff does to an account tells other servers nothing new (owner decision 2026-10-17): no `Flag`,
+`Block`, `Update` or `Delete` is sent for a silence or a suspension, and none is undone when it is lifted.
+
+- **A persona silenced here** stays out of this server's public and hashtag timelines, trends, directory and search,
+  and its posts no longer go to the relays. Everything else is as before: its actor, its collections, and every
+  delivery to its followers and to the accounts it addresses.
+- **A persona suspended here** (by the staff, or with its login banned) delivers nothing, takes no new follower (a
+  `Follow` is left unanswered, as one waiting for a locked account's approval), and its outbox, followers, following,
+  featured collections, posts, activities, replies, contexts, wall and quote permissions answer 404, signed or not. Its
+  actor document, its inbox (202, as ever) and WebFinger stay exactly as they were, so lifting the suspension serves
+  everything again without telling anyone it happened. A post of it removed meanwhile is deleted here only. The one thing
+  it may still send is the `Delete` of itself, if it is deleted.
+- **An account elsewhere suspended here:** what it sends is dropped after the 202, but a `Delete` or an `Undo`; nothing
+  is addressed to it, and nothing goes to its own inbox (its server's shared inbox still serves the others there).
+  Silenced, its posts stay out of the public timelines here. Its server hears of neither.
+- **A server silenced** (a domain block of `silence`) has its accounts' posts kept out of the public timelines here, as a
+  silenced account's are; a suspended one is refused at the inbox, as before.
+- **A post removed** by the staff: one of ours is deleted as its author would delete it (a `Delete` to its audience); a
+  copy of one from elsewhere is hidden here and never taken in again, and its server is not told.
+- **A persona or a group deleted** (by its login, its owner or an administrator): a `Delete` of the actor to its
+  followers, the accounts it follows and a group's members elsewhere; its documents answer 410 from then on, and its name
+  is never given again.
+
 ## Server descriptions and the crawler
 
 PrivaPub keeps statistics about servers, never about accounts (see `/stargazing` on the server).