feat(phase-26): add Campaign models, endpoints, service with kill chain timeline UI (T-217 to T-220)

frontend/src/components/Sidebar.tsx

@@ -14,6 +14,7 @@ import {
   ClipboardList,
   Database,
   Crosshair,
+  Zap,
 } from "lucide-react";
 import { useAuth } from "../context/AuthContext";
 
@@ -39,6 +40,7 @@ const mainLinks: NavItem[] = [
   },
   { to: "/reports", label: "Reports", icon: BarChart3 },
   { to: "/threat-actors", label: "Threat Actors", icon: Crosshair },
+  { to: "/campaigns", label: "Campaigns", icon: Zap },
 ];
 
 const adminLinks: NavItem[] = [