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/itsm-ng.json

@@ -0,0 +1,35 @@
+{
+  "name": "ITSM-NG",
+  "slug": "itsm-ng",
+  "categories": [
+    25
+  ],
+  "date_created": "2025-07-01",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 80,
+  "documentation": "https://wiki.itsm-ng.org/en/home",
+  "website": "https://itsm-ng.com",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/itsm-ng.webp",
+  "config_path": "/etc/itsm-ng",
+  "description": "ITSM-NG is a powerful, open-source IT Service Management (ITSM) solution designed for managing IT assets, software, licenses, and support processes in accordance with ITIL best practices. It offers integrated features for asset inventory, incident tracking, problem management, change requests, and service desk workflows.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/itsm-ng.sh",
+      "resources": {
+        "cpu": 2,
+        "ram": 2048,
+        "hdd": 10,
+        "os": "debian",
+        "version": "13"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": "itsm",
+    "password": "itsm"
+  },
+  "notes": []
+}