fix(windows): resolve CLI detection and process spawning on Windows

[MabuhayDesignsandCo]

Summary

Fixes Windows compatibility issues where claude-flow fails to detect Claude Code CLI and fails to spawn processes correctly on Windows.

Root cause: On Windows, the which command doesn't exist (it's where), and spawn/spawnSync/execSync calls need shell: true to resolve executables from PATH.

Changes

File	Fix
hive-mind.ts	Use where instead of which on win32 for Claude CLI detection
hive-mind.ts	Enable shell: process.platform === 'win32' for claude process spawn
auto-install.ts	Enable shell for npm spawnSync on Windows for PATH resolution
headless-worker-executor.ts	Enable shell for claude --version check and claude spawn
doctor.ts	Enable shell for npm install in installClaudeCode()

Additional Windows issues found (not in this PR)

During investigation, 47+ additional instances of missing Windows compatibility were identified across the codebase:

• statusline-generator.ts: Unix-style 2>/dev/null redirections, missing shell options
• init.ts: Unix-style & background operator, 2>/dev/null redirections
• security.ts: Missing shell options for npm audit commands
• browser-tools.ts: Missing shell for agent-browser spawn
• gcs.ts: Hardcoded /tmp paths (should use os.tmpdir())
• container-worker-pool.ts: Missing shell for docker spawn
• Various other files with Unix-specific shell assumptions

Recommendation: Consider adding a shared shellOption() helper:

const shellOption = () => process.platform === 'win32';

Testing

Tested on:

• OS: Windows 11
• Shell: PowerShell + Git Bash
• Node.js: v22+ (via nvm)
• Claude Code: v2.1.34
• claude-flow: v3.1.0-alpha.3

All three core scenarios now work:

1. claude-flow doctor correctly detects Claude Code CLI
2. claude-flow swarm successfully spawns Claude instances
3. claude-flow mcp start auto-installs packages via npm

Closes #615