HF RL Explorer

Refactor websocket dial into its own package with extensible options

Refactor websocket dial into its own package with extensible options: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). Right now the websocket client lives in pkg/conn alongside the generic Conn interface and RetryableError , and the dial entrypoint looks like:

The task

Right now the websocket client lives in `pkg/conn` alongside the generic `Conn` interface and `RetryableError`, and the dial entrypoint looks like:

Part of FineEnvs/MiMo-V2.6-RL-harbor-code.