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/projectsend.json

@@ -0,0 +1,40 @@
+{
+  "name": "ProjectSend",
+  "slug": "projectsend",
+  "categories": [
+    12
+  ],
+  "date_created": "2025-01-20",
+  "type": "ct",
+  "updateable": true,
+  "privileged": false,
+  "interface_port": 80,
+  "documentation": "https://docs.projectsend.org/",
+  "website": "https://projectsend.org/",
+  "logo": "https://cdn.jsdelivr.net/gh/selfhst/icons@main/webp/projectsend.webp",
+  "config_path": "/opt/projectsend/includes/sys.config.php",
+  "description": "ProjectSend is a free, open source software that lets you share files with your clients, focused on ease of use and privacy. It supports clients groups, system users roles, statistics, multiple languages, detailed logs... and much more!",
+  "install_methods": [
+    {
+      "type": "default",
+      "script": "ct/projectsend.sh",
+      "resources": {
+        "cpu": 1,
+        "ram": 1024,
+        "hdd": 8,
+        "os": "debian",
+        "version": "13"
+      }
+    }
+  ],
+  "default_credentials": {
+    "username": null,
+    "password": null
+  },
+  "notes": [
+    {
+      "text": "After running the update script, logging in as a system user in ProjectSend is necessary to upgrade the database.",
+      "type": "info"
+    }
+  ]
+}