windows: console window flashes on every subprocess spawn (v2 next build) #42440

Summary

On Windows, every time the agent runs a shell command (git, node, PowerShell, etc.), a console window briefly flashes open and then disappears. This happens for every command execution during a session.

Environment

• opencode version: 0.0.0-next-17428
• OS: Windows 11 Home 25H2, build 10.0.26200.8875 (win32 x64)
• Terminal: TERM=xterm-256color, COLORTERM=truecolor (opencode TUI)
• Shell: C:\WINDOWS\system32\cmd.exe
• Install/channel: next (@opencode-ai/[email protected])
• Active plugins: herdr-agent-state.js, rtk.ts

Reproduction

1. Run opencode2 on Windows.
2. Ask the agent to perform any task that runs a shell command (e.g. git status, ls, or any command).
3. Observe a console window flash on screen each time a command runs.

Expected Behavior

Subprocesses spawned for shell command execution run silently with no visible console window.

Actual Behavior

A black console window briefly appears and closes for every subprocess spawn. This is caused by subprocess spawning on Windows not setting the CREATE_NO_WINDOW creation flag (windowsHide: true in Node.js, HideWindow: true in Go's syscall.SysProcAttr).

Additional Context

• Service is healthy: opencode2 service status returns http://127.0.0.1:49374, /api/health returns {"healthy":true,"version":"0.0.0-next-17428"}.
• Reproducible consistently.
• Root cause is the same as the known v1 issues (Desktop app: Console window flashes repeatedly even while idle (CREATE_NO_WINDOW missing) #22414, Windows: subprocess spawn (git, codegraph, etc.) flashes console window #31629): missing CREATE_NO_WINDOW flag on Windows subprocess spawns. This report is for the v2 next build, where the flashing is still present.