PR Summary

Medium Risk
Updates command-line parsing used to spawn the ACPX target process; while scoped to Windows heuristics, mistakes could prevent Claude sessions from launching or mis-handle arguments on Windows.

Overview
Fixes ACPX mcp-proxy command parsing on Windows by preserving backslashes and correctly handling unquoted absolute .exe/.com paths (including paths with spaces) before spawning the child process.

Refactors parsing into reusable helpers, adds a narrow Windows executable-path fast path, and gates runtime execution behind an isMainModule check so the parser can be imported for tests. Adds regression tests covering quoted/unquoted Windows executable paths and Windows path-valued arguments, and updates the changelog entry for the fix.

^{Reviewed by Cursor Bugbot for commit 1f520f2. Bugbot is set up for automated code reviews on this repo. Configure here.}

Landed via temp rebase onto main.

• Gate: direct Node parser assertions; pnpm check reached unrelated pre-existing extensions/voice-call/src/config-compat.ts errors on origin/main; pnpm build advanced through the full build pipeline in this workspace but its shell wrapper did not return cleanly
• Land commit: 1f520f2
• Merge commit: db177ab

Thanks @steipete!

Greptile Summary

This PR fixes a real Windows bug where splitCommandLine treated \ as a universal escape character, silently dropping backslashes from Windows paths (e.g., C:\Users\file.exe became C:Usersfile.exe). The fix adds platform-aware backslash handling in splitCommandParts, a regex-based splitWindowsExecutableCommand to correctly extract unquoted Windows exe paths with spaces, and an isMainModule() guard that lets the .mjs file be safely imported in tests. The three new regression tests are well-targeted and the isMainModule() pattern is idiomatic ESM.

Confidence Score: 5/5

Safe to merge — the fix is narrow and well-tested, Unix behavior is unchanged, and the Windows path logic is correctly guarded by platform checks.

All findings are P2 or lower. The core logic (regex, win32 backslash semantics, isMainModule guard) is correct and matches the intended behavior. The three new tests directly reproduce the failure mode from #50352. No regressions to existing Unix parsing paths are introduced.

No files require special attention.

_{Reviews (1): Last reviewed commit: "docs: add changelog for #60689" | Re-trigger Greptile}