Generate a random 256-bit token when spawning a proxy process, pass
it as a CLI argument, and return it to the client in the stream start
response. The proxy validates the token on WebTransport connect and
consumes it after first use, preventing replay. A wrong token attempt
also consumes the token for security. Includes 5 unit tests for token
validation logic.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>