fix: stop aggressive API polling and SSE reconnect when auth lost

When unauthenticated (TOTP gate active), the dashboard was polling
/api/v1/services/status every few seconds and reconnecting SSE every
2-8s indefinitely. Now: 401/403 sets _dcAuthLost flag to skip the
polling interval, and SSE stops after 5 consecutive failures.

status/js/core/grid.js

@@ -401,9 +401,15 @@
     refreshInFlight = (async () => {
       try {
         const response = await fetch('/api/v1/services/status', { cache: 'no-store' });
+        if (response.status === 401 || response.status === 403) {
+          // Auth lost — stop the polling loop from hammering every few seconds
+          window._dcAuthLost = true;
+          throw new Error(`Authentication required (${response.status})`);
+        }
         if (!response.ok) {
           throw new Error(`Status refresh failed (${response.status})`);
         }
+        window._dcAuthLost = false; // auth working again
         const data = await response.json();
         applyBatchResults(data.statuses || {});
         updateStamp('last check', data.checkedAt || new Date());