The session file gives full access to the account. If it leaks, remove
the device in Linked devices on the phone.
+External events
+===============
+
+Use ``onechat notify --source CHECK --id EVENT --text TEXT`` to send
+external data to the root at its next turn. Add ``--agent-id ID`` to
+select a permanent child by its stable ID. Success means accepted, not
+processed. See ``onechat notify --help`` for the local test limits.
+
User service
============