diff --git a/PLAN.md b/PLAN.md
index 404f902..35e26dd 100644
--- a/PLAN.md
+++ b/PLAN.md
@@ -45,7 +45,7 @@ independent (see ARCHITECTURE §9.1).
 | 9 | Telegram integration (bot side-service, deep-link, push) | **done** |
 | 10 | Admin & dictionary ops (complaint review, version reload) | **done** |
 | 11 | Account linking & merge | **done** |
-| 12 | Observability & performance (telemetry, metrics, guest GC) | todo |
+| 12 | Observability & performance (telemetry, metrics, guest GC) | **done** |
 | 13 | Alphabet on the wire (UI alphabet-agnostic) | todo |
 | 14 | CI & deploy (multi-service, dictionary artifacts) | todo |