Some customers use mTLS device certificates to authenticate Coder CLI and VSCode extension with Coder instead of the Access Token. Add support for authenticating via mTLS device certs. We support this already in our VS Code extension which was contributed by @coryb. <img width="866" alt="Image" src="https://github.com/user-attachments/assets/759f5f33-3b9d-4cbf-958c-cf606c873ece" />
