[BUG] Session cost summary no longer displayed on Ctrl+C Ctrl+C exit since 2.1.49

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?

Prior to version 2.1.49, Claude Code would display a session cost summary (total cost, token usage, duration) when exiting the session with Ctrl+C Ctrl+C. After updating to 2.1.49, this summary no longer appears — the process just terminates silently without showing the cost.

This appears to be a regression introduced by the Ctrl+C handling changes for background agents in 2.1.49.

Steps to reproduce:

1. Start a Claude Code session and perform any interaction
2. Press Ctrl+C twice to exit
3. No session cost summary is shown

Expected behavior: Session cost summary is displayed on exit (as it was in previous versions)

Actual behavior: Session exits silently with no cost summary

Version: 2.1.49 (Claude Code) on macOS Darwin 25.2.0

What Should Happen?

When exiting Claude Code by pressing Ctrl+C twice, the session cost summary should be displayed before the process terminates — showing total cost, token usage, and session duration, as it did in versions prior to 2.1.49.

Error Messages/Logs

No error messages are shown. The session exits silently with no output — that is the bug itself.

Steps to Reproduce

Steps to reproduce:

1. Start a Claude Code session and perform any interaction
2. Press Ctrl+C twice to exit
3. No session cost summary is shown

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.49 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_