Add certbot status to dashboard services and sidebar nav indicator

- Add certbot to getDaemonStatus: checks binary availability and version
- Dashboard: add Certificates card to services grid
- Sidebar: show green/red status dot for certbot on Certificates nav item

web/src/components/DashboardComponent.tsx

@@ -8,7 +8,7 @@ import { Badge } from './ui/badge';
 import {
   LayoutDashboard, Cloud, CheckCircle, XCircle, AlertCircle, Loader2,
   BookOpen, Globe, Router, RotateCw, Key, KeyRound,
-  Shield, Eye, ArrowLeftRight, Lock,
+  Shield, ShieldCheck, Eye, ArrowLeftRight, Lock,
 } from 'lucide-react';
 import { useCloudflare } from '../hooks/useCloudflare';
 import { useCentralStatus } from '../hooks/useCentralStatus';
@@ -23,6 +23,7 @@ const SERVICES = [
   { key: 'wireguard', label: 'VPN', icon: Lock },
   { key: 'crowdsec', label: 'CrowdSec', icon: Eye },
   { key: 'authelia', label: 'Auth', icon: KeyRound },
+  { key: 'certbot', label: 'Certificates', icon: ShieldCheck },
 ];
 
 function formatUptime(totalSeconds: number): string {