Windows: subprocess spawn (git, codegraph, etc.) flashes console window #31629

// Current (flashes):
child_process.spawn('powershell.exe', ['-Command', 'git status'])

// Fixed (no flash):
child_process.spawn('powershell.exe', ['-Command', 'git status'], {
  windowsHide: true,
  stdio: 'pipe'
})

### Plugins

codegraph

### OpenCode version

opencode Desktop v1.14.49

### Steps to reproduce

### Description

When using the opencode Desktop on Windows (v1.14.49), every subprocess spawned via the `bash`/`shell` tool briefly opens a new console window (git.exe, powershell.exe, codegraph.cmd, etc.) which then immediately disappears. This causes a distracting flashing effect on the desktop.

### Affected Commands

- Any `bash` tool call → `powershell.exe` → child process (git.exe, sha256sum, etc.)
- MCP tools that use `.cmd` scripts (e.g., `codegraph.cmd`)
- `git-commit` and `code-review-gate` skills that frequently invoke `git diff`, `git status`, `git add`, `git commit`

### Root Cause

The Electron/Node.js `child_process.spawn` calls in opencode's desktop app do not set the Windows `CREATE_NO_WINDOW` flag. Node.js `spawn` accepts the `windowsHide: true` option, which when combined with `stdio: 'pipe'`, passes `CREATE_NO_WINDOW` (0x08000000) to `CreateProcessW`, suppressing the new console window.

### Expected Behavior

```js
// Current (flashes):
child_process.spawn('powershell.exe', ['-Command', 'git status'])

// Fixed (no flash):
child_process.spawn('powershell.exe', ['-Command', 'git status'], {
  windowsHide: true,
  stdio: 'pipe'
})

### Screenshot and/or share link

_No response_

### Operating System

Windows 10/11

### Terminal

_No response_