[BUG] Claude Desktop (Windows): orphaned processes after close block relaunch

What's Wrong?

Closing Claude Desktop on Windows frequently leaves ~9 Claude processes running (0% CPU). These orphans hold the app's single-instance lock, so relaunching the app fails silently until the processes are killed manually. This has been happening for months, across app updates.

Steps to Reproduce

1. Use Claude Desktop normally (local Filesystem MCP server enabled).
2. Close the app.
3. Check Task Manager: multiple Claude processes remain, idle at 0% CPU.
4. Try to relaunch Claude Desktop: nothing happens (no window, no error).

Workaround

Kill all Claude processes in Task Manager (or reboot), then the app launches normally.

Expected Behavior

Closing the app should terminate/reap all helper processes, or a relaunch should detect and recover from stale instances instead of failing silently.

Environment

• Platform: Windows (x64)
• Claude Desktop: latest at time of filing
• Local MCP: Filesystem server enabled