feat: remove legacy frontend, root routing, compliance ZIP with Chromium PDF, chat markdown styling

- Legacy frontend removed: React SPA served at / (no /app/ prefix)
- Compliance report ZIP: Chromium headless --print-to-pdf (identical to browser) + CSV findings
- Server-side generation state: .compliance_generating marker survives page navigation
- RAG enriched: Description + Rationale + Remediation + Audit extracted from CIS vector chunks
- Chat markdown: syntax highlighting (Catppuccin), styled headings/lists/tables/blockquotes/code
- Default model auto-selected on Chat Agent load

frontend-react/src/pages/ReportsPage.tsx

@@ -577,7 +577,6 @@ export default function ReportsPage() {
   const [showCompliance, setShowCompliance] = useState(false);
   const [complianceReady, setComplianceReady] = useState(false);
   const [complianceGenerating, setComplianceGenerating] = useState(false);
-  const compliancePollRef = useRef<ReturnType<typeof setInterval> | null>(null);
 
   /* ── Error ── */
   const [error, setError] = useState('');
@@ -625,12 +624,17 @@ export default function ReportsPage() {
       if (running && !trackingId) {
         setTrackingId(running.id);
       }
+      // Auto-select most recent completed report if none selected
+      if (!selectedRid && data.length > 0) {
+        const completed = data.find((r) => r.status === 'completed');
+        if (completed) setSelectedRid(completed.id);
+      }
     } catch (err) {
       setError(err instanceof Error ? err.message : t('rpt.errorLoadReports'));
     } finally {
       setReportsLoading(false);
     }
-  }, [trackingId]);
+  }, [trackingId, selectedRid]);
 
   useEffect(() => { loadReports(); }, []);  // eslint-disable-line react-hooks/exhaustive-deps
 
@@ -672,14 +676,14 @@ export default function ReportsPage() {
     Promise.all([
       reportsApi.summary(selectedRid),
       reportsApi.files(selectedRid),
-      reportsApi.complianceReportStatus(selectedRid).catch(() => ({ ready: false })),
+      reportsApi.complianceReportStatus(selectedRid).catch(() => ({ ready: false, generating: false } as { ready: boolean; generating: boolean })),
     ])
       .then(([summaryData, filesData, compStatus]) => {
         if (!cancelled) {
           setKpi(summaryData);
           setFiles(filesData);
-          setComplianceReady(compStatus.ready);
-          setComplianceGenerating(false);
+          setComplianceReady(!!compStatus.ready);
+          setComplianceGenerating(!!compStatus.generating);
         }
       })
       .catch(() => {
@@ -695,43 +699,34 @@ export default function ReportsPage() {
     return () => { cancelled = true; };
   }, [selectedRid]);
 
-  /* ── Compliance report polling (useEffect-based, survives re-renders + tab throttle) ── */
-  useEffect(() => {
-    if (!complianceGenerating || !selectedRid) return;
-    let active = true;
-    const check = async () => {
+  /* ── Compliance report polling (uses same usePolling as CIS report) ── */
+  usePolling(
+    async () => {
+      if (!complianceGenerating || !selectedRid) return false;
       try {
         const s = await reportsApi.complianceReportStatus(selectedRid);
-        if (s.ready && active) {
+        if (s.ready) {
           setComplianceReady(true);
           setComplianceGenerating(false);
           setShowCompliance(true);
+          return true; // stop polling
         }
       } catch { /* keep polling */ }
-    };
-    check();
-    const id = setInterval(check, 3000);
-    compliancePollRef.current = id;
-    const timeout = setTimeout(() => { clearInterval(id); if (active) setComplianceGenerating(false); }, 300000);
-    return () => { active = false; clearInterval(id); clearTimeout(timeout); compliancePollRef.current = null; };
-  }, [complianceGenerating, selectedRid]);
-
-  /* ── Re-check compliance status when section is expanded ── */
-  useEffect(() => {
-    if (!showCompliance || !selectedRid || complianceReady || complianceGenerating) return;
-    reportsApi.complianceReportStatus(selectedRid)
-      .then((s) => { if (s.ready) setComplianceReady(true); })
-      .catch(() => {});
-  }, [showCompliance, selectedRid, complianceReady, complianceGenerating]);
+      return false;
+    },
+    3000,
+    complianceGenerating && !!selectedRid,
+  );
 
   const startComplianceGeneration = useCallback(async () => {
-    if (!selectedRid) return;
-    setComplianceGenerating(true);
+    if (!selectedRid || complianceGenerating) return;
     setComplianceReady(false);
+    setComplianceGenerating(true);
     try {
       await reportsApi.generateComplianceReport(selectedRid);
     } catch { /* ignore */ }
-  }, [selectedRid]);
+    // polling is already running via usePolling above
+  }, [selectedRid, complianceGenerating]);
 
   /* ── Handlers ── */
   const handleRun = async () => {
@@ -1337,7 +1332,14 @@ export default function ReportsPage() {
                     style={{ height: 700, background: '#fff' }}
                     title="LAD A-Team CIS Compliance Report"
                   />
-                  <div className="px-5 py-2 flex justify-end" style={{ borderTop: '1px solid var(--bd)' }}>
+                  <div className="px-5 py-2 flex justify-end gap-2" style={{ borderTop: '1px solid var(--bd)' }}>
+                    <a
+                      href={reportsApi.complianceReportZipUrl(selectedRid)}
+                      className="flex items-center gap-1.5 px-3 py-1.5 rounded-lg text-[.68rem] font-medium cursor-pointer transition-colors no-underline"
+                      style={{ background: 'var(--ac)', color: '#fff' }}
+                    >
+                      <Download size={12} /> Download ZIP
+                    </a>
                     <button
                       onClick={startComplianceGeneration}
                       disabled={complianceGenerating}