diff --git a/AGENTS.md b/AGENTS.md
index 891c77f..cfa9901 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -102,5 +102,11 @@ the PR.
 
 **Deploy gotcha (still true):** the Spark needs a *dedicated* per-repo Gitea deploy key + a `Host`
 alias (the default `immense-voyage.local` block uses matrix-bridge's key); Gitea won't reuse one SSH
-key across repos' deploy keys. A Spark Control tile is captured in the inbox. **Next:** clear
-ten31-site's orphaned PR #4 thread (reply `clear` in its thread). Future redeploys: `ssh modelo32`.
+key across repos' deploy keys. A Spark Control tile is captured in the inbox. PR #4's orphaned thread
+was cleared this session by direct Matrix redaction (the bot couldn't — see the known issue below);
+future redeploys: `ssh modelo32`.
+
+**Known issue / next fix:** the poll loop prunes a PR's thread root from state when it leaves the open
+list (`src/bot.py` ~L594) *without redacting* — so a PR merged/closed **outside** the bot (e.g. the
+Gitea web UI) still orphans its thread, un-redactable by the bot afterward. The merge-redact fix
+covers bot-driven merges; the prune should redact the thread before dropping the root.