Replaces the axios HTTP call in js-src/Websocket.ts with the native fetch API.
Context: the axios ecosystem has been targeted by supply-chain attacks (e.g. https://www.malwarebytes.com/blog/news/2026/03/axios-supply-chain-attack-chops-away-at-npm-trust). Removing the dependency shrinks the package's attack surface and eliminates a vector for malicious or compromised axios releases.
No runtime behaviour change for consumers.