By: Michael Lynch <git@mtlynch.io>
Build and cache every package through flake checks Make checks.all depend on every exported package so nix flake check covers the complete build without shell-side target enumeration. Upload the aggregate closure only after checks succeed, and resolve its system from Nix itself. Backport refactoring-english-feedback fc756dc. Offline script tests cover option forwarding, optional hooks, failures, and uploads invoked outside the checkout.