chore(orbit): symmetric host-presence badge — green online / yellow offline

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/locales/en.ts

@@ -1488,6 +1488,7 @@ export const enTranslation = {
     catchUpLabel: 'catch up',
     catchUpTooltip: "Jump to the host's current position",
     hostAway: 'Host offline',
+    hostOnline: 'Host online',
     endTooltip: 'End session',
     leaveTooltip: 'Leave session',
     participantsInviteLabel: 'Invite link',