[BUG] Cache expiry warning shown in VS Code extension but not in terminal CLI on --resume

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?

When resuming a session that has been idle for days, the VS Code extension shows a warning like Idle 3d 7h. The prompt cache has likely expired, so your next message will re-cache about 594k tokens.

The same session resumed from the terminal with claude --resume shows no such warning.

Environment

CLI: 2.1.272 (Windows, PowerShell)
VS Code extension: anthropic.claude-code 2.1.270
Plan: Max subscription

What Should Happen?

Expected: the warning should appear in both clients, since the cache state is a property of the session, not the client.

Error Messages/Logs

Steps to Reproduce

Leave a session with large context idle for several days
Open the workspace in VS Code — warning appears
Run claude --resume in PowerShell, select the same session — no warning

Expected: the warning appears in both clients, since the cache state is a property of the session, not the client

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.272

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_