BACKEND_WS_URL was set to https://, but new WebSocket() requires a ws://wss:// scheme and throws a SyntaxError otherwise. Also removes the Firefox-only CSP override that worked around Firefox upgrading a plaintext ws:// dev connection to wss:// — now that the backend is real wss:// behind TLS, there's nothing left to upgrade. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Tn7uDYjTuZEbLPwpEiSCUw