Add local SQLite database and sync with Uptime Kuma

Features:
- SQLite database to track monitors and hosts locally
- Uses Uptime Kuma tags to mark monitors as managed by Kuma Strapper
- Sync on startup, before each scan, and on-demand via API
- Shows existing monitors when re-scanning a host

New files:
- backend/services/database.py - SQLite database service
- backend/services/sync.py - Sync service for Uptime Kuma reconciliation

API endpoints:
- POST /api/sync - Full sync with Uptime Kuma
- POST /api/sync/host/<hostname> - Sync specific host
- GET /api/hosts - List tracked hosts
- GET /api/hosts/<hostname>/monitors - Get monitors for host
- GET /api/monitors/tracked - Get all tracked monitors

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/App.jsx

@@ -17,6 +17,7 @@ export default function App() {
   const [scanProgress, setScanProgress] = useState({});
   const [scanResults, setScanResults] = useState({});
   const [analysisResults, setAnalysisResults] = useState({});
+  const [existingMonitors, setExistingMonitors] = useState({});
   const [kumaAuth, setKumaAuth] = useState({ authenticated: false, url: '' });
   const [showKumaLogin, setShowKumaLogin] = useState(false);
 
@@ -94,6 +95,13 @@ export default function App() {
       setPendingApprovals(prev => prev.filter(r => r.id !== request.id));
     });
 
+    socket.on('host_sync_complete', (data) => {
+      setExistingMonitors(prev => ({
+        ...prev,
+        [data.hostname]: data.existing_monitors || [],
+      }));
+    });
+
     return () => {
       socket.off('connect');
       socket.off('disconnect');
@@ -105,6 +113,7 @@ export default function App() {
       socket.off('analysis_error');
       socket.off('approval_request');
       socket.off('approval_resolved');
+      socket.off('host_sync_complete');
     };
   }, []);
 
@@ -183,6 +192,7 @@ export default function App() {
           scanProgress={scanProgress}
           scanResults={scanResults}
           analysisResults={analysisResults}
+          existingMonitors={existingMonitors}
           devMode={settings.dev_mode}
         />
       </main>

frontend/src/api/client.js

@@ -81,4 +81,13 @@ export const api = {
     body: JSON.stringify({ username, password, totp }),
   }),
   kumaLogout: () => fetchApi('/kuma/logout', { method: 'POST' }),
+
+  // Sync
+  triggerSync: () => fetchApi('/sync', { method: 'POST' }),
+  syncHost: (hostname) => fetchApi(`/sync/host/${encodeURIComponent(hostname)}`, { method: 'POST' }),
+
+  // Hosts and tracked monitors
+  getHosts: () => fetchApi('/hosts'),
+  getHostMonitors: (hostname) => fetchApi(`/hosts/${encodeURIComponent(hostname)}/monitors`),
+  getTrackedMonitors: () => fetchApi('/monitors/tracked'),
 };

frontend/src/components/Dashboard.jsx

@@ -3,7 +3,7 @@ import { api } from '../api/client';
 import HostCard from './HostCard';
 import DiscoveryResults from './DiscoveryResults';
 
-export default function Dashboard({ scanProgress, scanResults, analysisResults, devMode }) {
+export default function Dashboard({ scanProgress, scanResults, analysisResults, existingMonitors, devMode }) {
   const [hostname, setHostname] = useState('');
   const [username, setUsername] = useState('root');
   const [port, setPort] = useState('22');
@@ -133,6 +133,7 @@ export default function Dashboard({ scanProgress, scanResults, analysisResults,
           scanId={currentScanId}
           scan={currentScan}
           analysis={currentAnalysis}
+          existingMonitors={existingMonitors?.[hostname] || []}
           devMode={devMode}
           onCommandApproved={async (command) => {
             await api.runCommand(currentScanId, command, 'User approved from UI');

frontend/src/components/DiscoveryResults.jsx

@@ -1,7 +1,7 @@
 import { useState } from 'react';
 import { api } from '../api/client';
 
-export default function DiscoveryResults({ scanId, scan, analysis, devMode, onCommandApproved, onQuestionAnswered }) {
+export default function DiscoveryResults({ scanId, scan, analysis, existingMonitors, devMode, onCommandApproved, onQuestionAnswered }) {
   const [selectedMonitors, setSelectedMonitors] = useState([]);
   const [creatingDefaults, setCreatingDefaults] = useState(false);
   const [creatingSuggested, setCreatingSuggested] = useState(false);
@@ -194,6 +194,66 @@ export default function DiscoveryResults({ scanId, scan, analysis, devMode, onCo
                 </div>
               )}
 
+              {/* Existing Monitors */}
+              {existingMonitors && existingMonitors.length > 0 && (
+                <div className="mb-6">
+                  <h4 className="font-medium mb-3 flex items-center gap-2">
+                    <svg className="w-4 h-4 text-green-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                      <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12l2 2 4-4m6 2a9 9 0 11-18 0 9 9 0 0118 0z" />
+                    </svg>
+                    Existing Monitors ({existingMonitors.length})
+                    <span className="text-xs text-slate-400 font-normal">
+                      Already tracked for this host
+                    </span>
+                  </h4>
+                  <div className="space-y-2">
+                    {existingMonitors.map((monitor, index) => (
+                      <div
+                        key={index}
+                        className={`p-3 rounded ${
+                          monitor.status === 'deleted_in_kuma'
+                            ? 'bg-red-900/20 border border-red-800'
+                            : 'bg-slate-700/30 border border-slate-600'
+                        }`}
+                      >
+                        <div className="flex items-center gap-3">
+                          <span className={`w-2 h-2 rounded-full ${
+                            monitor.status === 'active' ? 'bg-green-400' :
+                            monitor.status === 'paused' ? 'bg-yellow-400' :
+                            monitor.status === 'deleted_in_kuma' ? 'bg-red-400' :
+                            'bg-slate-400'
+                          }`}></span>
+                          <span className={`px-2 py-0.5 text-xs font-medium rounded ${
+                            monitor.type === 'http' ? 'bg-blue-900 text-blue-200' :
+                            monitor.type === 'tcp' ? 'bg-green-900 text-green-200' :
+                            monitor.type === 'docker' ? 'bg-cyan-900 text-cyan-200' :
+                            monitor.type === 'push' ? 'bg-purple-900 text-purple-200' :
+                            monitor.type === 'ping' ? 'bg-emerald-900 text-emerald-200' :
+                            'bg-slate-600 text-slate-200'
+                          }`}>
+                            {monitor.type.toUpperCase()}
+                            {monitor.push_metric && (
+                              <span className="ml-1 opacity-75">({monitor.push_metric})</span>
+                            )}
+                          </span>
+                          <span className="text-slate-300">{monitor.name}</span>
+                          {monitor.status === 'deleted_in_kuma' && (
+                            <span className="ml-auto text-xs text-red-400">
+                              Deleted in Uptime Kuma
+                            </span>
+                          )}
+                          {monitor.status === 'paused' && (
+                            <span className="ml-auto text-xs text-yellow-400">
+                              Paused
+                            </span>
+                          )}
+                        </div>
+                      </div>
+                    ))}
+                  </div>
+                </div>
+              )}
+
               {/* Suggested Monitors */}
               {analysis.monitors && analysis.monitors.length > 0 && (
                 <div>