feat: implement skills marketplace API with CRUD operations and gateway integration

frontend/src/components/organisms/DashboardSidebar.tsx

@@ -11,6 +11,7 @@ import {
   Building2,
   LayoutGrid,
   Network,
+  Package,
   Settings,
   Tags,
 } from "lucide-react";
@@ -195,6 +196,20 @@ export function DashboardSidebar() {
                   Gateways
                 </Link>
               ) : null}
+              {isAdmin ? (
+                <Link
+                  href="/skills"
+                  className={cn(
+                    "flex items-center gap-3 rounded-lg px-3 py-2.5 text-slate-700 transition",
+                    pathname.startsWith("/skills")
+                      ? "bg-blue-100 text-blue-800 font-medium"
+                      : "hover:bg-slate-100",
+                  )}
+                >
+                  <Package className="h-4 w-4" />
+                  Skills
+                </Link>
+              ) : null}
               {isAdmin ? (
                 <Link
                   href="/agents"

frontend/src/components/organisms/UserMenu.tsx

@@ -11,6 +11,7 @@ import {
   ChevronDown,
   LayoutDashboard,
   LogOut,
+  Package,
   Plus,
   Server,
   Settings,
@@ -155,6 +156,7 @@ export function UserMenu({
               { href: "/activity", label: "Activity", icon: Activity },
               { href: "/agents", label: "Agents", icon: Bot },
               { href: "/gateways", label: "Gateways", icon: Server },
+              { href: "/skills", label: "Skills", icon: Package },
               { href: "/settings", label: "Settings", icon: Settings },
             ] as const
           ).map((item) => (