[BUG] Windows: .node native addon cache files accumulate in working directory (~100GB/week)

Description

Claude Code is creating .node native addon cache files in the working directory that are never cleaned up. These files accumulate rapidly, consuming ~100GB of disk space per week of normal usage.

Environment

• OS: Windows 11 (Git Bash / MSYS2)
• Claude Code version: 2.1.27 (issue started around v2.1.17-v2.1.19)
• Working directory: D:\_temp\user

Files

The files follow this naming pattern:

• .789d7ff3ba6e7b0e-00000000.node (hidden files, ~7MB each)
• 24ea8bd7-f3f2-4885-8550-924d329e7804.tmp.node (~876KB each)

$ file D:/_temp/user/.789d7ff3ba6e7b0e-00000000.node
PE32+ executable for MS Windows 6.00 (DLL), x86-64, 7 sections

These appear to be better-sqlite3 native addons extracted by Bun at runtime (as noted in #14911).

Observed Behavior

• ~15,680 .node files accumulated over ~7 days
• Total disk usage: ~103GB
• New files are created during active sessions (observed ~14 files created within minutes)
• Files are NOT cleaned up when sessions end
• Files persist across Claude Code restarts

Timeline

• First observed file date: January 24, 2026
• This coincides with v2.1.17 (Jan 22) which included "Fixed crashes on processors without AVX instruction support" - possibly related to native module build/load changes

Steps to Reproduce

1. Run Claude Code on Windows with a custom working directory
2. Use Claude Code normally for several days
3. Check working directory for .*.node files

ls -la D:/_temp/user/.*.node | wc -l
# Returns thousands of files

Expected Behavior

• Native addon cache files should be cleaned up when no longer needed
• Or, cache should be reused instead of creating new files for each session/operation
• Or, files should be created in a proper temp directory that gets cleaned up

Workaround

Manual cleanup:

rm D:/_temp/user/.*.node

Or scheduled task to periodically delete these files.

Related Issues

• #14911 - macOS Gatekeeper warning for extracted .node native addon (identifies the file origin)
• #18711 - Windows: tmpclaude-*-cwd temp files not being cleaned up (similar cleanup issue)

Additional Context

This is on a project with custom agents (27) and hooks, but the hooks only invoke PowerShell scripts and don't directly use Node.js. The accumulation rate suggests this is related to subagent spawning or general Claude Code operation rather than project-specific configuration.