feat(phase-22): add import services for Sigma, LOLBAS, GTFOBins, CALDERA, Elastic and data sources panel (T-203 to T-207)

frontend/src/components/Sidebar.tsx

@@ -12,6 +12,7 @@ import {
   ChevronDown,
   ListChecks,
   ClipboardList,
+  Database,
 } from "lucide-react";
 import { useAuth } from "../context/AuthContext";
 
@@ -41,6 +42,7 @@ const mainLinks: NavItem[] = [
 const adminLinks: NavItem[] = [
   { to: "/users", label: "Users", icon: Users },
   { to: "/audit", label: "Audit Log", icon: FileText },
+  { to: "/data-sources", label: "Data Sources", icon: Database },
   { to: "/system", label: "System", icon: Settings },
 ];