[Windows] Each prompt spawns 3–5 git.exe processes that each open a visible console window

Environment: Windows 11 Enterprise 10.0.26200; Git 2.55.0.windows.5; Claude Code 2.1.289. The git.exe count below was measured on 2026-09-26 and has not been re-measured on 2.1.289. claude is launched by a local web UI as a child process, one per conversation.

What happens: every prompt makes claude.exe (and its bun.exe children) spawn about 3–5 git.exe processes. Each one gets its own console window, which flashes on screen and steals focus. Screen-reader runs (NVDA) were interrupted twice by the focus change.

Ruled out: the UI starts claude.exe with creationflags=CREATE_NO_WINDOW. A stand-in test ruled out grandchildren allocating their own consoles because of CREATE_NO_WINDOW. Giving claude.exe a hidden console changed nothing. With CLAUDE_CODE_DISABLE_GIT_INSTRUCTIONS=1 it still spawned 3 git.exe per send, the same as without it.

Expected: git subprocesses run without a visible console (CREATE_NO_WINDOW / windowsHide), as they do when Claude Code runs in a terminal.