[BUG] /context header and category breakdown disagree after session restart + mid-session model switch

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?

/context shows two mutually contradictory accountings in the same panel:

• Header: 357.8k / 1.0M tokens (36%)
• Category table: Messages alone = 691.6k (69.2%); all categories sum

to 711.5k used + Free space 288.5k (28.8%) = exactly 1.0M.

The table is internally consistent, the header is internally consistent,
but they can't both be true (36% used vs 71.2% used). The progress bar
follows the table (~70% filled), not the header.

Full breakdown shown:

| Category | Tokens | Usage |
|---------------|--------|-------|
| System prompt | 3.9k | 0.4% |
| System tools | 12.1k | 1.2% |
| Memory files | 2.5k | 0.2% |
| Skills | 1.4k | 0.1% |
| Messages | 691.6k | 69.2% |
| Free space | 288.5k | 28.8% |

The ~2:1 ratio (691.6k vs 357.8k) suggests one number is the raw stored
transcript and the other is the auto-compacted working set, rendered
together without reconciliation.

What Should Happen?

Header, progress bar, and category table agree on one number for
context usage.

Error Messages/Logs

Steps to Reproduce

1. Run a long session (multi-day, heavy tool use) on a model with a

1m window until context runs low.

1. Restart the machine / IDE and resume the same session.
2. Switch models mid-session via /model to a different 1M-context variant

(claude-fable-5[1m]).

1. Run /context.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.156 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Environment

• Claude Code: 2.1.156 (Claude Code)
• Interface: VS Code extension (panel), version 2.1.170
• OS: Windows 11
• Model at time of bug: claude-fable-5[1m] (switched mid-session from a

claude-opus-4.8[1m])