[BUG] Context usage is always 100% free

Environment

• Platform (select one):
• [x] Anthropic API
• Claude CLI version: v1.0.95
• Operating System: macOS 15.6.1
• Terminal: Visual Code

Bug Description

When I used /context command to display the current context usage.
<img width="1075" height="798" alt="Image" src="https://github.com/user-attachments/assets/3f502def-89af-4785-84f0-e109fb43de9f" />

Steps to Reproduce

1. type /context
2. the context usage comes out.

Expected Behavior

Display the actual context usage

Actual Behavior

Always display the context usage is 100% free.