An interrupted extract leaves node_modules/get-windows without package.json
and npm never revisits an existing directory, so the tree stayed broken on
every later update until a manual `npm install get-windows`. Delete such a
dir (workspace hoist or app-local copy) in _install_desktop_workspace_deps
before npm runs so the same update re-extracts it; the staging repair hint
now points at `hermes desktop --force-build` instead of the manual install.
Also drops the unused `exists` injection on findHalfInstalledGetWindowsDir
and the stale "exported for tests" note on missingGetWindowsWarning.