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/nextpvr.json

@@ -0,0 +1,35 @@
+{
+  "name": "NextPVR",
+  "slug": "nextpvr",
+  "categories": [
+    13
+  ],
+  "date_created": "2024-11-20",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 8866,
+  "documentation": "https://github.com/sub3/NextPVR/wiki",
+  "website": "https://nextpvr.com/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/nextpvr.webp",
+  "config_path": "/var/opt/nextpvr/config.xml",
+  "description": "NextPVR is a personal video recorder application for Microsoft Windows, Linux, Mac and Docker. NextPVR makes it easy to watch or record live TV, and provides great features like series recordings, web scheduling, iPhone/iPad client application, Kodi/Emby integration etc.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/nextpvr.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 1024,
+        "hdd": 5,
+        "os": "debian",
+        "version": "13"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": "admin",
+    "password": "password"
+  },
+  "notes": []
+}