refactor: remove frontend, move JSONs to json/ top-level

- Archive frontend to community-scripts/ProxmoxVE-Frontend-Archive
- Move frontend/public/json/ -> json/
- Update workflow paths in 5 actions:
  - update-versions-github.yml
  - update-json-date.yml
  - push-json-to-pocketbase.yml
  - delete-pocketbase-entry-on-removal.yml
  - autolabeler.yml
- Remove frontend-cicd.yml (no longer needed)
- Clean up .gitignore (remove frontend-specific entries)

json/openwrt-vm.json

@@ -0,0 +1,41 @@
+{
+  "name": "OpenWrt",
+  "slug": "openwrt-vm",
+  "categories": [
+    4,
+    2
+  ],
+  "date_created": "2024-05-02",
+  "type": "vm",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": null,
+  "documentation": "https://openwrt.org/docs/start",
+  "website": "https://openwrt.org/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/openwrt.webp",
+  "config_path": "",
+  "description": "OpenWrt is a powerful open-source firmware that can transform a wide range of networking devices into highly customizable and feature-rich routers, providing users with greater control and flexibility over their network infrastructure.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "vm/openwrt-vm.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 256,
+        "hdd": 0.5,
+        "os": null,
+        "version": null
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": null,
+    "password": null
+  },
+  "notes": [
+    {
+      "text": "If you use VLANs (default LAN is set to VLAN 999), make sure the Proxmox Linux Bridge is configured as VLAN-aware, otherwise the VM may fail to start.",
+      "type": "info"
+    }
+  ]
+}