A pane whose organization's bus is stopped or unavailable no longer polls or offers Refresh; it says
nothing is read until the bus starts again, holds any typed draft, and restores it untouched when the
bus returns. Unsent pane drafts now count for the organization-switch and Console-restart guards.
The Assistant sidebar item drops the Messages unread badge. "Start thread" is the primary action.
Tests cover the stopped pane's draft, a reply arriving with no refresh, and an uppercase show id.