Town: Misskey's renote count outlives an undone boost (G-0005)

decePub's e2e boost on Misskey undoes its boost and finds the count still
up: Misskey deletes the renote but its NoteDeleteService lowers only
repliesCount. Recorded as a peer gap, so the cell is a known failure.

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

docs/INTEROP.md

@@ -333,6 +333,11 @@ Firefish is dead (its site has answered 410 since February 2025).
 
 A new Misskey 2026 starts with `federation: none`.
 
+Misskey never lowers a post's `renoteCount` when a renote is deleted, so a remote boost undone with `Undo{Announce}`
+still counts there (G-0005; its `NoteDeleteService` lowers only `repliesCount`). Sharkey lowers it. It also counted a
+boost twice when the same `Announce` reached it twice at once, which PrivaPub no longer does: a boost goes to the
+author's server once, through its shared inbox.
+
 **Pasture evidence (2026-10-03, Sharkey 2025.4.7, `tools/pasture/scenarios/sharkey.sh`):** 40 checks pass, the whole
 Misskey scenario under Sharkey's name and then what only Sharkey does:
 - its edits arrive as edits, and ours reach it;