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/notifiarr.json

@@ -0,0 +1,40 @@
+{
+  "name": "Notifiarr",
+  "slug": "notifiarr",
+  "categories": [
+    14
+  ],
+  "date_created": "2024-06-12",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 5454,
+  "documentation": "https://notifiarr.wiki/",
+  "website": "https://notifiarr.com/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/notifiarr.webp",
+  "config_path": "/etc/notifiarr/notifiarr.conf",
+  "description": "Notifiarr is a purpose built system to bring many applications together to manage and customize notifications via Discord. You can monitor many aspects of your network(s), be notified of downtime, be notified of health issues, etc",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/notifiarr.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 512,
+        "hdd": 2,
+        "os": "debian",
+        "version": "13"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": null,
+    "password": null
+  },
+  "notes": [
+    {
+      "text": "Manually edit `/etc/notifiarr/notifiarr.conf`to enter the API key from Notifiarr.com, and create a password for the UI.",
+      "type": "info"
+    }
+  ]
+}