Install/update completion rewrites the root install-stamp.json (fresh
builtAt) after products are built, and the stamp was still a shared
web/desktop source input, so every install left its own web_dist
"missing, stale, or damaged" and the post-install probe failed on every
installer E2E leg. Nothing in either build reads the root stamp;
desktop's baked stamp is already tracked as a prepared input.
b3618bda35