Move Uptime Kuma from Infrastructure to Operations in the sidebar

It watches over things rather than being a machine/platform itself,
closer in spirit to Maintenance than to Proxmox or Tailscale. Also
balances the two groups (6/2 -> 5/3).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/layout/AppShell.tsx

@@ -67,7 +67,6 @@ const NAV: NavEntry[] = [
       { to: "/synology", label: "Synology", icon: <IconDatabase size={20} /> },
       { to: "/docker", label: "Docker", icon: <IconBrandDocker size={20} /> },
       { to: "/tailscale", label: "Tailscale", icon: <IconAffiliate size={20} /> },
-      { to: "/uptime-kuma", label: "Uptime Kuma", icon: <IconActivityHeartbeat size={20} /> },
     ],
   },
   {
@@ -97,6 +96,7 @@ const NAV: NavEntry[] = [
     icon: <IconTool size={20} />,
     items: [
       { to: "/maintenance", label: "Maintenance", icon: <IconTool size={20} /> },
+      { to: "/uptime-kuma", label: "Uptime Kuma", icon: <IconActivityHeartbeat size={20} /> },
       { to: "/generator", label: "Generator", icon: <IconWand size={20} /> },
     ],
   },