CVE-2026-35214: Budibase: Path traversal in plugin file upload enables arbitrary directory deletion and file write

The plugin file upload endpoint (POST /api/plugin/upload) passes the user-supplied filename directly to createTempFolder() without sanitizing path traversal sequences. An attacker with Global Builder privileges can craft a multipart upload with a filename containing ../ to delete arbitrary directories via rmSync and write arbitrary files via tarball extraction to any filesystem path the Node.js process can access.