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/bitmagnet.json

@@ -0,0 +1,51 @@
+{
+  "name": "Bitmagnet",
+  "slug": "bitmagnet",
+  "categories": [
+    11
+  ],
+  "date_created": "2025-05-15",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 3333,
+  "documentation": "https://bitmagnet.io/setup.html",
+  "website": "https://bitmagnet.io/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/bitmagnet.webp",
+  "config_path": "`/opt/bitmagnet/config.yml` or `/opt/bitmagnet/.env`",
+  "description": "A self-hosted BitTorrent indexer, DHT crawler, content classifier and torrent search engine with web UI, GraphQL API and Servarr stack integration.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/bitmagnet.sh",
+      "resources": {
+        "cpu": 2,
+        "ram": 1024,
+        "hdd": 4,
+        "os": "debian",
+        "version": "13"
+      }
+    },
+    {
+      "type": "alpine",
+      "script": "ct/alpine-bitmagnet.sh",
+      "resources": {
+        "cpu": 2,
+        "ram": 1024,
+        "hdd": 3,
+        "os": "alpine",
+        "version": "3.23"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": null,
+    "password": null
+  },
+  "notes": [
+    {
+      "text": "During installation you will be asked to enter your TMDB API key, if you wanna use it. Make sure you have it ready.",
+      "type": "info"
+    }
+  ]
+}