[BUG] Max plan 5-hour limit jumped to 33% in ~18 minutes with no activity

**Plan:** Max
**Client:** Claude desktop app (Code tab), macOS
**Date:** 2026-09-15, 5-hour window resetting 2026-09-16 01:00 UTC

## What happened
The 5-hour usage limit jumped to 33% in about 18 minutes while I was not using Claude.

- 5-hour limit: 33%
- Weekly, all models: 22%
- Weekly, Fable: 25%

## What was checked
- No scheduled tasks and no cron jobs exist.
- No session was running during that period. The sessions I opened afterwards were started after the jump, and I only asked short questions in them.

## Expected
Usage should not be consumed when nothing is running.

## Ask
1. Identify what consumed this usage on my account.
2. Add a per-session / per-surface usage breakdown so users can see where the limit goes.

The report names no repository files, tests, or entry points. Start by investigating usage telemetry for the stated 18-minute window and comparing Claude desktop activity with the 5-hour limit; done means identifying what consumed the usage or documenting that attribution is unavailable, with a scoped plan for per-session and per-surface breakdowns.

Written by the indexing model from the issue text.