Two bugs caught in the second VM end-to-end run:
1. electron-builder's winCodeSign extraction fails on grandma-class
Windows boxes because the .7z archive contains macOS symlinks
(darwin/10.12/lib/libcrypto.dylib and libssl.dylib pointing at
versioned siblings). Creating symlinks on Windows requires
SeCreateSymbolicLinkPrivilege, a per-user right that non-admin
accounts don't have on stock Windows. Result: every fresh install
on a non-admin user fails Stage-Desktop with a 7-Zip 'cannot create
symbolic link' error, retried four times, then bails.
Fix: Initialize-ElectronBuilderCache pre-extracts winCodeSign-2.6.0.7z
ourselves with -snl (don't preserve symlinks, store as resolved file
content) AND -x!darwin (skip the entire macOS subtree — irrelevant
on Windows). Writes to electron-builder's expected cache dir before
electron-builder gets a chance to try its own broken extraction.
Idempotent — fast-paths via signtool.exe sentinel check.
2. Install-Desktop's first guard was 'if (-not $HasNode) skip'.
$HasNode is set by Stage-Node into $script:HasNode, but in
cross-process driver mode (each -Stage NAME is a fresh powershell.exe
spawned by Hermes-Setup.exe), that script-scope variable from the
PREVIOUS process is invisible — so the guard always fired and
Install-Desktop returned in 900ms with a misleading
'Node.js not available' reason. The real npm probe below it never
got to run. Fix: re-probe npm directly via Get-Command when $HasNode
is empty/false, since by that point Stage-Node has already verified
Node is installed and the only question is whether *this* process
can see it on PATH (it can — installer-wide PATH update from Stage-Node).