Add Telegram Codex usage command

README.md

@@ -14,6 +14,7 @@ only keeps connection-management commands.
 /repo <path-under-workspace-root>
 /ask <prompt>
 /work <prompt>
+/usage
 /new
 /status
 /settings
@@ -51,6 +52,8 @@ explicitly.
 `/settings`, `/models`, `/schedules`, `/records`, and `/sessions` return inline
 buttons, so you can change speed/model/reasoning settings, delete schedules,
 manage personal records, and switch or archive sessions without copying ids.
+`/usage` asks the local Codex app-server for account, plan, rate-limit, and
+credit information when the installed Codex version exposes it.
 
 ## Runtime settings