Description
Summarises sessions over a window: which repos, how many turns, what it cost, how long tools took, what failed. It ships in the runtime image because it is only useful where the transcripts are.
Acceptance Criteria
- #1 -since and -namespace bound the window
- #2 Summarises per session and per repo: turns, tokens, cost where known, tool outcomes, failures and interruptions
- #3 Claude-only and Codex-only figures are labelled rather than shown as zero
- #4 Output is readable in a terminal and has a -json form
Definition of Done
- #1 just check passes: fmt-check, lint, build, test-short, probe-ci, dashboard-check and docs-links all clean