/usage Session view shows stale or cross-session data

Summary

The /usage command's Session view appears to display data that's either stale (not refreshed in-session) or carries over from a prior session, making it unreliable as a real-time cost monitor during long agent runs.

Environment

• Claude Code CLI: 2.1.143
• macOS 15.x
• Model: Opus 4.7 (1M context)

Repro

Observed during an extended multi-agent orchestration session on 2026-05-17/18 (~$30+ in real API spend across one session). Session view values didn't track with spend reported by other instrumentation, and didn't update after large bursts of tool calls.

Don't have a tight repro yet — flagging that the field may not be trustworthy as a mid-session cost gauge. Happy to gather more data on the next long run.

Expected

Session-scoped totals should reflect the current session's actual spend, updated within a reasonable interval of the most recent API call.