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/elementsynapse.json

@@ -0,0 +1,48 @@
+{
+  "name": "Element Synapse",
+  "slug": "elementsynapse",
+  "categories": [
+    4
+  ],
+  "date_created": "2025-02-02",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 8008,
+  "documentation": "https://element-hq.github.io/synapse/latest/welcome_and_overview.html",
+  "website": "https://element.io/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/element.webp",
+  "config_path": "/etc/matrix-synapse/homeserver.yaml",
+  "description": "Synapse is an open source Matrix homeserver implementation, written and maintained by Element. Matrix is the open standard for secure and interoperable real time communications. You can directly run and manage the source code in this repository, available under an AGPL license. There is no support provided from Element unless you have a subscription.",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/elementsynapse.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 2048,
+        "hdd": 8,
+        "os": "debian",
+        "version": "13"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": null,
+    "password": null
+  },
+  "notes": [
+    {
+      "type": "info",
+      "text": "Type `cat ~/matrix.creds` to see admin username/password."
+    },
+    {
+      "type": "info",
+      "text": "Synapse-Admin is running on port 5173"
+    },
+    {
+      "type": "info",
+      "text": "For bridges Installation methods (WhatsApp, Signal, Discord, etc.), see: ´https://docs.mau.fi/bridges/go/setup.html´"
+    }
+  ]
+}