Windows smoke test exits code=0 because requestSingleInstanceLock()
fails silently when the APPDATA/<productName> directory doesn't exist.
Pre-create the directory so the lock file can be written.
Also enables ELECTRON_SMOKE_STREAM_LOGS=1 in CI for better debugging.
Integrated into release/v3.7.1 — fixes Electron installer shipping empty node_modules. Adds separate extraResources FileSet, CI smoke test job, and cross-platform packaged app validation script. Closes#1636.