Replies a post's author approves (FEP-5624), checked live with PeerTube

PeerTube puts canReply on a video whose comments wait for approval, and answers each comment with ApproveReply. A
persona's reply to such a post now waits (privapub.approval: pending), its Create going to the author alone; the
author's ApproveReply, signed by the author and naming the post answered, lets it out to its audience with
replyApproval, and RejectReply leaves it ours. A null canReply (PeerTube's open comments) says nothing; an empty one
refuses. The PeerTube scenario holds a comment for review and approves it through PeerTube's API (28 checks).

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

docs/ROADMAP.md

@@ -679,7 +679,9 @@ it, raw where it doesn't.
   - `indexable`/`discoverable`/`searchableBy`;
   - edit history from `formerRepresentations`: **done 2026-10-06** (Pleroma's and Akkoma's earlier versions, for a post
     met after its edits and for the edits missed in between);
-  - PeerTube reply rules and `ApproveReply`.
+  - PeerTube reply rules and `ApproveReply`: **done 2026-10-06** (FEP-5624's `canReply`: a reply waits for the author's
+    `ApproveReply` or `RejectReply`, going to the author alone until then; checked live against PeerTube's moderated
+    comments).
 - **Events:** structured RSVP (`Join`/`Leave` with stable ids): **done 2026-10-05** (owner decision above), checked live
   against Mobilizon.