[BUG] [Windows] Claude Code 2.1.139 still hangs after all documented workarounds (spawn EINVAL, blank -p output, interactive hang)

Summary

On native Windows with @anthropic-ai/claude-code 2.1.139, both the VS Code extension and the native CLI remain unusable after applying every documented workaround. This is a regression that's been live since at least 2026-04-18 (see #50616, closed as duplicate but with symptoms unresolved on the affected machine).

Environment

• Windows (version unconfirmed)
• PowerShell
• @anthropic-ai/claude-code 2.1.139 (claude --version confirms)
• VS Code with Claude Code extension
• Git Bash at C:\Program Files\Git\bin\bash.exe

Symptoms

1. VS Code sidebar: every session fails with Error: spawn EINVAL.
2. Non-interactive CLI: claude -p "Respond with exactly OK" exits 0 with blank stdout.
3. Interactive CLI: claude from PS C:\Arduino> spawns C:\Users\<user>\AppData\Roaming\npm\node_modules\@anthropic-ai\claude-code\bin\claude.exe (observed PID 26060) and produces no visible response until the process is killed externally.

Workarounds attempted (none resolve the hang)

• Removed bad local claudeCode.claudeProcessWrapper VS Code setting
• npm install -g @anthropic-ai/claude-code@2.1.139
• Set CLAUDE_CODE_GIT_BASH_PATH=C:\Program Files\Git\bin\bash.exe (Windows User env + VS Code claudeCode.environmentVariables)
• Enabled claudeCode.useTerminal=true

User impact

This is not a minor configuration issue. The VS Code sidebar is the primary interface, and with both it and the fallback CLI broken there is no trusted native-Windows workflow. Sidebar-session work has had to be emergency-recovered. Current personal workaround is SSH into a Linux box for serious work — that's avoiding the product, not a fix.

Please treat as an active Windows reliability outage rather than a duplicate of a closed thread. Happy to provide debug logs, environment dumps, or attempt requested diagnostics.