chore: Use availability in dashboard presence toggle (#3212)

app/views/api/v1/models/_user.json.jbuilder

@@ -21,6 +21,9 @@ json.accounts do
     json.name account_user.account.name
     json.active_at account_user.active_at
     json.role account_user.role
+    # the actual availability user has configured
+    json.availability account_user.availability
+    # availability derived from presence
     json.availability_status account_user.availability_status
     json.auto_offline account_user.auto_offline
   end