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/grocy.json

@@ -0,0 +1,35 @@
+{
+  "name": "grocy",
+  "slug": "grocy",
+  "categories": [
+    24
+  ],
+  "date_created": "2024-05-02",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 80,
+  "documentation": "https://github.com/grocy/grocy#how-to-install",
+  "website": "https://grocy.info/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/grocy.webp",
+  "config_path": "/var/www/html/data/config.php",
+  "description": "grocy is a web-based self-hosted groceries & household management solution for your home. It helps you keep track of your groceries and household items, manage your shopping list, and keep track of your pantry, recipes, meal plans, and more.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/grocy.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 512,
+        "hdd": 2,
+        "os": "debian",
+        "version": "13"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": "admin",
+    "password": "admin"
+  },
+  "notes": []
+}