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/links.html

@@ -518,7 +518,13 @@ async function loadLinks() {
 }
 
 loadLinks();
-lt.autoRefresh.start(loadLinks, 60000);
+var _linksInterval = (window.gandalfSettings && window.gandalfSettings.refreshInterval) || 60;
+if (_linksInterval > 0) lt.autoRefresh.start(loadLinks, Math.max(_linksInterval, 15) * 1000);
+
+window.onGandalfSettingsChanged = function(s) {
+  lt.autoRefresh.stop();
+  if (s.refreshInterval > 0) lt.autoRefresh.start(loadLinks, Math.max(s.refreshInterval, 15) * 1000);
+};
 
 document.addEventListener('click', e => {
   const toggleTitle = e.target.closest('[data-action="toggle-panel"]');