Add notification bell, settings modal, and context-sensitive footer

- Notification bell in header polls /api/status and shows active alerts
  with severity-colored dots; badge counts unread items via localStorage
- Settings modal ([ * ] CFG) controls auto-refresh interval (15s/30s/1m/5m/off)
  persisted to localStorage and wired into lt.autoRefresh on all pages
- Context-sensitive footer hints: Dashboard shows REFRESH + SUPPRESS,
  Link Debug shows REFRESH, all pages show CFG + HELP
- Added S key (quick suppress) and * key (settings) shortcuts
- ⌘K affordance button added to header-right
- R key now uses lt.autoRefresh.now() so it works on any page
- refreshAll() pushes fresh events to notification bell on each poll

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

templates/index.html

@@ -463,7 +463,16 @@
 
 {% block scripts %}
 <script>
-  lt.autoRefresh.start(refreshAll, 30000);
+  // Start auto-refresh using saved settings interval (default 30 s)
+  var _savedInterval = (window.gandalfSettings && window.gandalfSettings.refreshInterval) || 30;
+  if (_savedInterval > 0) lt.autoRefresh.start(refreshAll, _savedInterval * 1000);
+
+  // When settings change, restart auto-refresh with new interval
+  window.onGandalfSettingsChanged = function(s) {
+    lt.autoRefresh.stop();
+    if (s.refreshInterval > 0) lt.autoRefresh.start(refreshAll, s.refreshInterval * 1000);
+  };
+
   document.getElementById('suppress-form')?.addEventListener('submit', submitSuppress);
   document.getElementById('sup-type')?.addEventListener('change', updateSuppressForm);