feat(site): enhance monitoring dashboard and public status pages

Implement incident tracking for public status pages, improve the monitoring
dashboard UI with better grouping and loading states, and refine domain
resolution logic.

- feat(hub): add incident support to public status pages
- feat(hub): implement immediate monitor checks on creation and resume
- feat(hub): improve domain status detection using DNS fallback when WHOIS fails
- feat(site): redesign monitoring dashboard with categorized cards
- feat(site): add incident detail view and management in the dashboard
- feat(site): add active incidents section to public status pages
- feat(site): add "Add System" functionality to systems table
- refactor(site): improve calendar view responsiveness and loading states
- style(site): add skeleton components for better UX during data fetching

internal/hub/monitors/scheduler.go

@@ -390,9 +390,15 @@ func (s *Scheduler) AddMonitor(record *core.Record) {
 func (s *Scheduler) UpdateMonitor(record *core.Record) {
 	m := recordToMonitor(record)
 
-	// Get existing scheduled monitor to preserve next check time if appropriate
+	// Get existing scheduled monitor
 	if sm, ok := s.monitors.GetOk(m.ID); ok {
 		sm.mu.Lock()
+		wasPaused := sm.Monitor.Status == monitor.StatusPaused || !sm.Monitor.Active
+		nowActive := m.Active && m.Status != monitor.StatusPaused
+		// If monitor just became active (resumed), reset NextCheck so it's checked immediately
+		if wasPaused && nowActive {
+			sm.NextCheck = time.Now()
+		}
 		sm.Monitor = m
 		sm.mu.Unlock()
 	} else {