* ci: run nix build on ubuntu and macos
* ci: use DeterminateSystems/nix-installer-action
* fix: wrong extension for mac
---------
Co-authored-by: pablo <p.lopez.lpz@gmail.com>
- Consolidate build and test into a single job to avoid duplicate builds;
artifact sharing across jobs proved too complex to justify
- NBS was the main bottleneck; this change improves CI duration beyond that
- Add caching for Cargo registry, git sources, and libchat's target
Add a smoke test that validates the binary links all dependencies
at runtime by instantiating a client without networking. Redesign
CI into separate build and test jobs, with test gated on build.