Fix card links on index pages: add section prefix to local hrefs

Links like /proxmox/ were missing the section prefix (e.g. /infra/proxmox/)
since all sites now share a single Eleventy build at root.

infra/index.njk

@@ -9,30 +9,30 @@ sections:
     cards:
       - title: "🖥️ Proxmox host (PVE)"
         summary: "Hosting environment for running production VMs and LXC containers for the homelab."
-        href: "/proxmox/"
+        href: "/infra/proxmox/"
       - title: "💾 Synology DS918+"
         summary: "NAS running Docker services and acting as the primary backup repository."
-        href: "/synology/"
+        href: "/infra/synology/"
       - title: "🐳 Docker VMs (Debian)"
         summary: "Primary target for new Docker/Compose services, running the monitoring exporters."
-        href: "/docker/"
+        href: "/infra/docker/"
       - title: "📦 LxC Container"
         summary: "Pi-hole, Ubuntu-Worker and MariaDB running on slim LxC Containers."
-        href: "/lxc/"
+        href: "/infra/lxc/"
   - heading: "Strategies & Setup-Guides"
     cards:
       - title: "🔄 Backup strategy"
         summary: "Layered backup approach covering NAS user content and VM/LXC backups across multiple locations."
-        href: "/backup-strategy/"
+        href: "/infra/backup-strategy/"
       - title: "📊 Prometheus/Grafana"
         summary: "Central metrics collection and dashboards for hosts, containers, and hardware."
-        href: "/monitoring/"
+        href: "/infra/monitoring/"
       - title: "💻 Dev environment"
         summary: "A disposable, daily-backed-up Xubuntu VM for AI-assisted, remote development via SSH and Chrome Remote Desktop."
-        href: "/dev-environment/"
+        href: "/infra/dev-environment/"
       - title: "🌐 OpenWrt Multi-WAN"
         summary: "Multi-WAN router with WiFi and Powerline failover, plus IoT VLAN 189 isolation."
-        href: "/openwrt/"
+        href: "/infra/openwrt/"
 ---
 <p class="site-intro">A peek under the hood of my homelab. Proxmox, Synology, Docker, and how everything is wired together.</p>