docs(changeset): add the multi-user admin-only settings fix

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.changeset/086dca20.md

@@ -19,6 +19,8 @@
 
 **A note after each update (#618).** The first time a browser loads a newer Codeman, a toast lists that release's headline changes, with a **See what's new** button that opens the full release notes. It shows once per version, and a browser that has never opened Codeman before just records the version and stays quiet, so the first note you will see is the one for the release after this one. The headlines are taken from the changelog when the release is cut.
 
+**Multi-user mode: only admins change server-wide settings.** In multi-user mode any signed-in regular user could rewrite the server's settings (feature switches, run mode, case order, the default model for cron and the orchestrator, the app config), start a self-update, rotate the tunnel QR code, clear stale session state, and sign every user out with Revoke All, admins included. They could also read the Deepgram API key an admin saved. Those writes and operations now answer 403 to a regular user, Revoke All signs them out of their own logins only, and their settings read leaves out the admin's key and case names. In the browser a regular user's per-device settings still save, a change to a server-wide setting shows one notice that only an admin can change it, instead of pretending it was saved, and their own run mode and respawn presets are kept on their device. Single-user mode is unchanged.
+
 **Fixes.**
 
 - **Codex submits long prompts (#628).** Prompts sent through the API, `codeman agent send`, the MCP server, cron or the agent skill go into the pane as one bracketed paste followed by a separate Enter, so Codex no longer leaves them sitting unsent in its composer. A single character (a menu answer like `3` or `y`) is still typed, so numbered dialogs keep picking the option you sent, and a trailing `;` survives, so `find . -exec rm {} \;` arrives whole.