chore(DC-161): record grade B (round 5) in changelog

urn:ump:znykdi6ufm53sgnhkep7ghlda7aoo55nipghjtstlkpqqmxuv2zq

CHANGELOG.md

@@ -21,6 +21,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   and registers the calendar source — the widget connects with zero user input.
   Manual bring-your-own sources (Radicale/Baikal/Nextcloud hosted elsewhere,
   iCloud/Fastmail CalDAV, plain ICS feeds) wire in through the settings modal.
+  Codex judge: **grade B (round 5)** —
+  urn:ump:znykdi6ufm53sgnhkep7ghlda7aoo55nipghjtstlkpqqmxuv2zq.
 
 ## [1.17.0] - 2026-10-07