[BUG] /context command shows inconsistent token usage between summary and breakdown

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

<img width="513" height="229" alt="Image" src="https://github.com/user-attachments/assets/54365bbe-d42f-4c2c-9122-e0d74d44579b" />

Description

The header line reported by /context doesn't match the sum of the individual category breakdowns.

Observed behavior

The summary line reports 74k/200k tokens (37%) used, but the category breakdown only accounts for ~51k tokens:

  ┌────────────────┬────────┐
  │    Category    │ Tokens │
  ├────────────────┼────────┤
  │ System prompt  │ 4k     │
  ├────────────────┼────────┤
  │ Custom agents  │ 701    │
  ├────────────────┼────────┤
  │ Memory files   │ 1.2k   │
  ├────────────────┼────────┤
  │ Skills         │ 614    │
  ├────────────────┼────────┤
  │ Messages       │ 41.2k  │
  ├────────────────┼────────┤
  │ Compact buffer │ 3k     │
  ├────────────────┼────────┤
  │ Sum            │ ~50.7k │
  └────────────────┴────────┘

The free space line also contradicts the header: 149k free (74.7%) implies only ~51k used (25.3%), not 74k (37%).

What Should Happen?

Expected behavior

The header total should equal the sum of the listed categories, and should be consistent with 200k - free space.

Error Messages/Logs

Steps to Reproduce

Reproduction

Run /context mid-conversation. The header and breakdown diverge by ~23k tokens.

Environment

• Model: claude-opus-4-6 (200k context)
• ~37% into a conversation per the header, ~25% per the breakdown

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.39 (Claude Code)

Platform

AWS Bedrock

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

I have auto-compact disabled - not sure if related.

<img width="1029" height="201" alt="Image" src="https://github.com/user-attachments/assets/665ba27c-4966-43dc-9c1b-76954507a924" />