Move CompanionIndicator from global App.vue overlay to DashboardSidebar
next to ControllerIndicator. Redesigned as inline sidebar element with
Tailwind classes — shows muted 'Relay' when idle, orange 'Companion'
with pulse dot when actively receiving input.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>