[BUG] VSCode extension continues executing tool calls after chat window is closed

Description

When closing the Claude Code chat window in VSCode during context compaction, the underlying process continues executing queued tool calls (file edits, bash commands) instead of terminating immediately.

Steps to Reproduce

1. Open Claude Code in VSCode
2. Give it a task that involves file edits and bash commands
3. While it is mid-compaction (context window compression), close the chat window
4. Observe that file modifications and shell commands continue to execute after the window is closed

Expected Behavior

Closing the chat window should immediately terminate all in-flight and queued tool calls. No further file system modifications or shell commands should execute.

Actual Behavior

Tool calls (Edit, Bash) continue executing after the window is closed. In this case, the session was compacting context when the window was closed, and the process continued making file edits and running shell commands silently.

Impact

This is a trust and safety issue. Users expect closing the window to stop all activity. Continuing to modify files silently undermines user control over their own machine.

Environment

• Platform: Windows 11 (10.0.26200)
• Extension: Claude Code VSCode extension