Global gitignore write fails on Windows with EEXIST (mkdir targets existing home dir)

Environment

• Claude Code: 2.1.211 (native installer, auto-updated from 2.1.206)
• OS: Windows 11 Pro (10.0.26200)

Summary

On startup, adding an entry to the global gitignore fails with EEXIST because
Claude Code attempts to mkdir the parent path that already exists (the user's
home directory), instead of treating "already exists" as success or using a
recursive mkdir.

Error (from debug log)

[ERROR] Failed to add gitignore entry to global gitignore:
EEXIST: file already exists, mkdir 'C:\Users\<user>'

Expected

The global gitignore entry is written; an already-existing parent directory is
not an error.

Actual

The write throws EEXIST and the error flashes on every startup. Appeared after
the 2.1.206 -> 2.1.211 update.