Session Trace view replaces Transcript and Timeline

In the UI: a session now opens on Trace, which replaces the Transcript
and Timeline tabs. A turn rail with a minimap leads to each turn’s steps: model
calls, tool calls, approvals, sub-agents and messages, with waterfall timing
bars. The step inspector shows input, output, the full model request and raw
events. Batches and sub-agents expand inline, search jumps to a hit, and j
and k move between steps. The view, error filter and selected step live in
the URL.
In code: read the same data from /v1/sessions/{id}/trace, or with
everruns sessions trace get and everruns sessions trace turns list.
See Web UI, the sessions CLI reference and #4481, #4500, #4503, #4556.