diff --git a/README.md b/README.md
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@@ -1,5 +1,10 @@
 # KeiSeiKit
 
+> **Tester notice (2026-04-23):** git history was rewritten to sanitise commit
+> subjects before public launch. If you have an existing clone, run
+> `git fetch --all && git reset --hard origin/main` to resync. Working tree
+> content is unchanged; only historical commit subjects differ.
+
 > A living neural structure you install next to your AI assistant.
 > A mini-universe where any user, from any domain, can discover a new primitive or grow a new class of agent.