Usage stats show token consumption during period when laptop was fully powered off

Description

The /usage dialog in Claude Code shows token consumption attributed to a time window when my laptop was fully shut down (not sleep/hibernate — fully powered off).

Steps to Reproduce

1. Use Claude Code for a session, then fully shut down the laptop (not sleep)
2. Boot the laptop the next morning and open Claude Code
3. Run /usage and check the \"Last 24h\" stats

Observed Behavior

The usage stats show activity during the hours the laptop was off. Specifically:

• Laptop was shut down at approximately 1 AM
• The /usage dialog shows usage characteristics (including >150k context sessions) attributed to time windows after shutdown
• ~15% of 24h usage appears to have occurred while the machine was off

Expected Behavior

No token consumption should be possible on a fully powered-off machine. The stats should show zero usage after shutdown time.

Investigation Done

• Checked CronList — no local cron jobs
• Checked remote routines via RemoteTrigger {action: "list"} — no scheduled remote agents
• No other devices or claude.ai sessions active
• The /usage dialog itself states: "Approximate, based on local sessions on this machine — does not include other devices or claude.ai"

Environment

• Platform: macOS (Darwin 25.2.0)
• Claude Code version: (latest as of 2026-06-07)

Notes

The stats say \"approximate\" but attributing usage to a powered-off machine suggests either a bug in the timestamp tracking logic or a background process waking/running unexpectedly. Worth investigating whether session log timestamps are written at consumption time vs. flush time (e.g., at shutdown).