Per-user Slipstream client bridging a logged-in user's support widget to CodeMySpec.

Connects server-side with an owner-approved installation credential (which never reaches the browser), joins conversation:<user_id>, and relays messages between CodeMySpec and the user's SupportWidgetLive over local PubSub. Chat and "Report a problem" both ride this one connection. Reconnects with backoff. Shared by applications through client_utils.