Build web v2 session workbench slice

[roackb2]

Summary

• wire web-v2 sidebar lists to control-plane sessions and heartbeat tasks
• render selected session conversations with v2-owned markdown/message components
• add the first visual-only composer with model and reasoning selectors
• add the missing web-v2 /trpc dev proxy

Verification

• yarn client:v2:build

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Handle rejected session queries to clear loading state

If trpc.controlPlane.session.query rejects (for example, transient network failure or server error), this effect never catches the exception, so loading remains true and the rejection is unhandled in the browser. Because setState({ session, loading: false }) is only reached on success, the session view can stay stuck in a perpetual loading state until a later successful fetch or remount.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Catch sidebar state query failures in one-shot loader

This one-shot sidebar loader runs only once ([] deps), but it does not handle errors from trpc.controlPlane.state.query. When that request fails, the promise rejection is unhandled and sessions/tasks stay at their initial empty arrays with no retry path, which leaves the navigation lists blank for the remainder of the mount.

Useful? React with 👍 / 👎.