Gate for contributor #4057 (same tip). cwd+stdout FD instead of -C/-f for Windows tar.exe ANSI argv; GNU tar --exclude for in-tree archive; resolve System32 tar.exe before cwd switch.
Local Codex CLEAN on 73ff25a31 (residual P2 glob-escape deferred). Electron smoke PASS NC_OUT pr-4057-73ff25a31. CI green on tip after plugin-manager focus flake retrigger.