Town: Iceshrimp.NET joins, and its mentions go nowhere new

Iceshrimp.NET 2026.1.2-beta runs in the pasture with AuthorizedFetch on;
its driver registers through the native API and takes Mastodon tokens from
its OAuth form. The pair passes 225 cells. A new Iceshrimp note reaches its
author's followers only, never an account it mentions or answers, until it
is edited (G-0004, peer): delivery cells now say when a server holds a post
only because it was addressed.

The checker credits a seeder's fetch to the object fetched, not to the reply
that needed it; the seeder skips the wait for an accept whose follow was
already accepted; the PrivaPub driver signs its roots in again when a run
reuses saved sessions.

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

docs/INTEROP.md

@@ -338,6 +338,14 @@ Misskey scenario under Sharkey's name and then what only Sharkey does:
 - its edits arrive as edits, and ours reach it;
 - its quote carries the FEP-e232 `Link` tag and is understood.
 
+**Town evidence (2026-10-05, Iceshrimp.NET 2026.1.2-beta, `town.sh seed iceshrimp-pair`):** 225 cells pass between
+two personas and three Iceshrimp accounts (AuthorizedFetch on): delivery and confinement at every visibility both
+ways, likes, boosts, emoji reactions and votes counted, threads, edits and deletes, follows of locked accounts on
+both sides, and the privacy rows. Two cells are Iceshrimp's own gap (G-0004): a new note goes to its author's
+followers only, so an account it mentions or answers gets it once it is edited, not when it is written (the Create's
+`pre-deliver` job lists no recipients, through the Mastodon and the native API alike). Its followers and following
+collections answer HTML to an ActivityPub `Accept`, so PrivaPub shows no counts for them.
+
 ### Pleroma 2.10.2 and Akkoma 3.20.1
 
 **Emits**