940b69b1a8
_handle_webhook() called request.read() with no size guard. Since the endpoint is publicly reachable, an attacker can send an arbitrarily large POST body to exhaust gateway memory. Add _TWILIO_WEBHOOK_MAX_BODY_BYTES (64 KiB — well above any real Twilio payload) and gate on both Content-Length and actual read size, returning HTTP 413 with an empty TwiML Response on oversized requests. Mirrors the guard already present in the Raft adapter.