Orchestrator -> Accumulated cost/metrics

When starting an orchestration session, I would like to see the token spend for the whole job. Preferably configurable so i can see it next to the title. Would be nice with a "Oh-my-posh" type of configurability there. ;)

Start by locating the orchestration-session startup flow and the UI entry point that renders the title. Clarify which token costs and metrics belong to the whole job, how users configure their display, and what the completed title or status presentation should show; no files or tests are named in the issue.

索引モデルが issue の本文から書いたものです。