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)

.gitignore

@@ -24,13 +24,6 @@ venv/
 env/
 *.env
 
-# Node.js dependencies (frontend folder was excluded, but keeping this rule for reference)
-frontend/node_modules/
-frontend/.svelte-kit/
-frontend/.turbo/
-frontend/.vite/
-frontend/build/
-
 # API and Backend specific exclusions
 api/.env
 api/__pycache__/