feat: implement finding archive tracking system

- Add migration script for ivanti_finding_archives and ivanti_archive_transitions tables
- Add archive detection logic (detectArchiveChanges, detectClosedFindings) in sync pipeline
- Add archive API router with list, stats, and history endpoints at /api/ivanti/archive
- Add ArchiveSummaryBar UI component with four state cards (ACTIVE, ARCHIVED, RETURNED, CLOSED)
- Integrate ArchiveSummaryBar into Ivanti findings page in App.js
- Register archive router in server.js

frontend/src/App.js

@@ -12,6 +12,7 @@ import VulnerabilityTriagePage from './components/pages/ReportingPage';
 import KnowledgeBasePage from './components/pages/KnowledgeBasePage';
 import ExportsPage from './components/pages/ExportsPage';
 import CompliancePage from './components/pages/CompliancePage';
+import ArchiveSummaryBar from './components/pages/ArchiveSummaryBar';
 import './App.css';
 
 const API_BASE = process.env.REACT_APP_API_BASE || 'http://localhost:3001/api';
@@ -233,6 +234,9 @@ export default function App() {
   const [ivantiLoading, setIvantiLoading] = useState(false);
   const [ivantiSyncing, setIvantiSyncing] = useState(false);
 
+  // Archive filter state
+  const [archiveFilter, setArchiveFilter] = useState(null);
+
   const toggleCVEExpand = (cveId) => {
     setExpandedCVEs(prev => ({ ...prev, [cveId]: !prev[cveId] }));
   };
@@ -369,6 +373,10 @@ export default function App() {
     }
   };
 
+  const handleArchiveStateClick = (state) => {
+    setArchiveFilter(prev => prev === state ? null : state);
+  };
+
   const fetchDocuments = async (cveId, vendor) => {
     const key = `${cveId}-${vendor}`;
     if (cveDocuments[key]) return;
@@ -2251,6 +2259,9 @@ export default function App() {
                   : 'Never synced'}
               </div>
 
+              {/* Archive Summary Bar */}
+              <ArchiveSummaryBar onStateClick={handleArchiveStateClick} activeFilter={archiveFilter} />
+
               {ivantiLoading ? (
                 <div className="text-center py-8">
                   <Loader className="w-6 h-6 text-teal-400 animate-spin mx-auto mb-2" />